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Publication Number: FHWA-HRT-04-144
Date: December 2005

Enhanced Night Visibility Series, Volume XIII: Phase III—Study 1: Comparison of Near Infrared, Far Infrared, High Intensity Discharge, and Halogen Headlamps on Object Detection in Nighttime Clear Weather

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Figure 1. Diagram. Bird’s-eye view of beam pattern of HID 1. The isocandela diagram shows the lighting footprint of the HID 1 headlamps from an overhead vantage point; the footprint is overlaid on a graph marked off in feet. The X-axis marks the forward lighting range in feet, and the Y-axis marks the side-to-side lighting range in feet. The peak range of the forward lighting pattern is at X equals about 165 feet (at Y equals 10 feet to the right of the vehicle’s center axis). The maximum illumination distance to the left side of the vehicle is just over Y equals 20 feet (at a forward distance from X equals around 20 to 60 feet). The maximum illumination distance to the right side of the vehicle is also just over Y equals 20 (at a forward distance from X equals around 20 to 60 feet). The illumination levels increase evenly in roughly concentric areas of intensity from the maximum illumination distance back to the light source. Back to Figure 1.

Figure 2. Diagram. Forward beam pattern of HID 1. The isocandela diagram shows the forward lighting footprint of the HID 1 headlamps from the vantage point of the driver; the footprint is overlaid on a graph marked off in degrees. The X-axis marks the side-to-side lighting range in degrees (negative values to the left of the vehicle’s center axis), and the Y-axis marks the vertical lighting range in degrees (negative values at levels below headlamp level). The maximum illumination distance to the left side of the vehicle is at around X equals negative 28 degrees (which occurs at Y equals negative 5 degrees, below the headlamp level). The maximum illumination distance to the right side of the vehicle is at around X equals 31 degrees (which occurs at around Y equals negative 2 degrees, below the headlamp level). The approximate vertical illumination range is from Y equals 0 degrees (at headlamp level) to Y equals negative 9 degrees (below headlamp level). This maximum range occurs at the midpoint of the vehicle (at X equals 0 degrees). The illumination levels increase evenly in roughly concentric areas of intensity from the maximum illumination distance back to the light source. Back to Figure 2.

Figure 3. Diagram. Bird’s-eye view of beam pattern of HID 2. The isocandela diagram shows the lighting footprint of the HID 2 headlamps from an overhead vantage point; the footprint is overlaid on a graph marked off in feet. The X-axis marks the forward lighting range (starting at around 19 feet), and the Y-axis marks the side-to-side lighting range in feet. The peak range of the forward lighting pattern is around X equals 148 feet (at Y equals 5 feet to the right of the vehicle center axis). The maximum illumination distance to the left side of the vehicle is at around Y equals 25 feet (at a forward distance from X equals around 60 to 75 feet). The maximum illumination distance to the right side of the vehicle is at around Y equals 34 feet (at a forward distance from X equals around 65 to 80 feet). The illumination levels increase evenly in roughly concentric areas of intensity from the maximum illumination distance back to the light source. Back to Figure 3.

Figure 4. Diagram. Forward beam pattern of HID 2. The isocandela diagram shows the forward lighting footprint of the HID 2 headlamps from the vantage point of the driver; the footprint is overlaid on a graph marked off in degrees. The X-axis marks the side-to-side lighting range in degrees (negative values to the left of the vehicle’s center axis), and the Y-axis marks the vertical lighting range in degrees (negative values at levels below headlamp level). The maximum illumination angles to the left and right side of the vehicle are both greater than 45 degrees (the graph’s negative and positive X-value limits are 45 degrees). The vertical illumination range is from around Y equals 2 degrees (above headlamp level) to lower than Y equals negative 10 degrees (below headlamp level), which is the negative limit of the Y-values on the graph. The maximum vertical value Y equals 2 degrees occurs at around 6 to 13 degrees to the right of the vehicle’s center axis. In general, the maximum vertical value occurs close to the vehicle’s center axis and falls steadily to below negative 10 degrees, both for the right and left sides of the graph. The illumination levels increase evenly in roughly concentric areas of intensity from the maximum illumination distance back to the light source.
Back to Figure 4.

Figure 5. Photo. Object: pedestrian, black clothing, left (black left, BlackLF). This photo shows a pedestrian wearing black scrubs standing on the left side of the road taken from the perspective of the participant’s vehicle in daylight. The pedestrian is standing just outside the far lane boundary on a straight segment of roadway. The pedestrian is standing with arms down to the side and facing the oncoming test vehicle.
Back to Figure 5.

Figure 6. Photo. Object: pedestrian, black clothing, right (black right, BlackRT). This photo shows a pedestrian wearing black scrubs standing on the right side of the road taken from the perspective of the participant’s vehicle in daylight. The pedestrian is standing just to the right of the participant’s right-hand lane boundary on a straight segment of roadway. The pedestrian is standing with arms down to the side and facing the oncoming test vehicle. Back to Figure 6.

Figure 7. Photo. Object: pedestrian, denim clothing, left (blue left, BlueLF). This photo shows a pedestrian wearing blue denim scrubs standing on the left side of the road taken from the perspective of the participant’s vehicle in daylight. The pedestrian is standing just outside the far lane boundary on a straight segment of roadway. The pedestrian is standing with arms down to the side and facing the oncoming test vehicle. Back to Figure 7.

Figure 8. Photo. Object: pedestrian, denim clothing, right (blue right, BlueRT). This photo shows a pedestrian wearing blue denim scrubs standing on the right side of the road as viewed from the participant vehicle in daylight. The pedestrian is standing just to the right of the participant’s right-hand lane boundary on a straight segment of roadway. The pedestrian is standing with arms down to the side and facing the oncoming test vehicle. Back to Figure 8.

Figure 9. Photo. Object: pedestrian in left turn, left side (left turn left, LFtrnLF). This photo shows a pedestrian wearing blue denim scrubs standing in a left-hand curve on the left side of the road from the perspective of the participant’s vehicle in daylight. The pedestrian is standing just outside the far lane boundary. The pedestrian is standing with arms down to the side and facing the oncoming test vehicle. Back to Figure 9.

Figure 10. Photo. Object: pedestrian in left turn, right side (left turn right, LFtrnRT). This photo shows a pedestrian wearing blue denim scrubs standing in a left-hand curve on the right side of the road as viewed from the perspective of the participant’s vehicle in daylight. The pedestrian is standing just to the right of the participant’s right-hand lane boundary. The pedestrian is standing with arms down to the side and facing the oncoming test vehicle. Back to Figure 10.

Figure 11. Photo. Object: pedestrian in right turn, left side (right turn left, RTtrnLF). This photo shows a pedestrian wearing blue denim scrubs standing in a right-hand curve and on the left side of the road as viewed from the perspective of the participant’s vehicle in daylight. The pedestrian is standing just outside the far lane boundary. The pedestrian is standing with arms down to the side and facing the oncoming test vehicle. Back to Figure 11.

Figure 12. Photo. Object: pedestrian in right turn, right side (right turn right, RTtrnRT). This photo shows a pedestrian wearing blue denim scrubs standing in a right-hand curve and on the right side of the road as viewed from the perspective of the participant’s vehicle in daylight. The pedestrian is standing just to the right of the participant’s right-hand lane boundary. The pedestrian is standing with arms down to the side and facing the oncoming test vehicle. Back to Figure 12.

Figure 13. Photo. Object: far off axis, left (FOALT). This photo shows a pedestrian wearing blue denim scrubs standing on the outside edge of the left shoulder of the road as viewed from the perspective of the participant’s vehicle in daylight. The pedestrian is standing with arms down to the side and facing the oncoming test vehicle. Back to Figure 13.

Figure 14. Photo. Object: far off axis, right (FOART). This photo shows a pedestrian wearing blue denim scrubs standing past the outside of the right shoulder as viewed from the perspective of the participant’s vehicle in daylight. The pedestrian is standing with arms down to the side and facing the oncoming test vehicle. Back to Figure 14.

Figure 15. Photo. Object: bloom object, left (bloom left, BloomLF). This photo is taken in daylight from the perspective of the participant’s vehicle. It shows a vehicle parked in the oncoming lane. The parked vehicle has its headlamps on. A pedestrian wearing blue denim scrubs is standing on the left side of the road just outside the far lane boundary and in line with the rear wheels of the parked vehicle. The pedestrian is standing with arms down to the side and facing the oncoming test vehicle. Back to Figure 15.

Figure 16. Photo. Object: bloom object, right (bloom right, BloomRT). This photo is taken in daylight from the perspective of the participant’s vehicle. It shows a vehicle parked in the oncoming lane. The vehicle has its headlamps on. A pedestrian wearing blue denim scrubs is standing on the right side of the road just to the right of the participant’s right-hand lane boundary and in line with the rear wheels of the parked vehicle. The pedestrian is standing with arms down to the side and facing the oncoming test vehicle. Back to Figure 16.

Figure 17. Photo. Object: dog. This photo is taken in daylight from the perspective of the participant’s vehicle. It shows a dog mockup placed on the centerline that divides the two lanes; the dog’s head is facing the participant’s lane of travel. Back to Figure 17.

Figure 18. Photo. Object: pavement marking turn arrow. This photo is taken in daylight from the perspective of the participant’s vehicle. It shows a left turn arrow made of retroreflective pavement tape placed in the center of the participant’s lane of travel. Back to Figure 18.

Figure 19. Photo. Object: Raised retroreflective pavement markers, RRPMs. This photo is taken in daylight from the perspective of the participant’s vehicle. It shows two RRPMs placed on the road, one before and one after a skip mark. The RRPMs are placed with the white, reflective side facing the oncoming test vehicle. Back to Figure 19.

Figure 20. Photo. Object: sign. This photo is taken in daylight from the perspective of the participant’s vehicle. It shows yield and speed limit signs placed to the right of the participant’s right-hand lane boundary. Signs are placed with the planes of the signs perpendicular to the lane of travel. Back to Figure 20.

Figure 21. Photo. Object: tire tread. This photo is taken in daylight from the perspective of the participant’s vehicle. It shows a tire tread centered on the right boundary line of the participant’s lane of travel.
Back to Figure 21.

Figure 22. Diagram. Subjective ratings scale. This is a seven-point Likert-type straight-line scale, from 1 (which equals Strongly Agree) on the left to 7 (which equals Strongly Disagree) on the right.
Back to Figure 22.

Figure 23. Photo. Data collection display screen. The photo shows a sample display screen used to record the data collected during an onroad trial. The top section displays general trial information, including the experimental setup (VES), condition, success code, target order, day, detection/recognition code, input file, event mark code, and IR button code. The middle section includes target order for the current run, location of the upcoming target, and running values for distance and speed. The bottom section allows the experimenter to modify the data collection process. Back to Figure 23.

Figure 24. Photo. Headlamp testing rack. This photo shows a testing rack mounted on the front of an SUV with experimental headlamps attached. Back to Figure 24.

Figure 25. Diagram. Smart Road layout with object locations. The diagram shows the entire roadway course of the Smart Road driven by participants during the study. The road is depicted as being fairly straight with one gradual curve toward the top. There is a turnaround loop at each end of the road and two turnarounds in the middle, labeled Turnaround 2 and Turnaround 3. The top turnaround is in the upper left corner of the diagram and the bottom turnaround is in the lower right corner, indicating that there is a grade. There are eleven arrows along the side of the road indicating the eleven locations where objects were presented, all on the same side of the road. From the top to the bottom of the road, there are two locations at the top turnaround, four locations following turnaround 2, three locations around turnaround 3, and two locations near the bottom turnaround of the road. Back to Figure 25.

Figure 26. Photo. Slow lead vehicle. This photo is taken from the perspective of the participant’s vehicle in daylight. It shows a vehicle onroad driving in front of the participant’s vehicle. Back to Figure 26.

Figure 27. Photo. Pass participant vehicle. This photo is taken from the perspective of the participant’s vehicle in daylight. It shows an onroad vehicle with its headlamps on coming toward the participant’s vehicle. This is a straight section of road. Back to Figure 27.

Figure 28. Photo. Crossing front vehicle. This photo is taken from the perspective of the participant’s vehicle in daylight. It shows an onroad vehicle with its headlamps on. The vehicle is perpendicular to the participant’s vehicle, and it appears to be driving from the right side of the road to the left side at a distance of approximately four skip marks in front of the participant’s vehicle. Back to Figure 28.

Figure 29. Photo. Crossing rear vehicle. This photo is taken from the perspective of facing the participant’s vehicle in daylight. Behind the participant’s vehicle is an onroad vehicle with its headlamps on. It appears that the vehicle is driving from one side of the road to the other perpendicular to and behind the participant vehicle, beginning in the same lane as the participant’s vehicle. Back to Figure 29.

Figure 30. Bar graph. Object detection means for the three age groups. The graph is titled “Detection—Age.” The Y-axis indicates detection distance in feet. The X-axis indicates age category (young, middle, and older). Each age category has one bar. Letters above each bar note the groupings for the means (means with the same letter are not significantly different) based on the Student-Newman-Keuls results. The overall detection distance for the young group is just over 700 feet, for the middle group it is just less than 700 feet, and for the older group it is approximately 550 feet. The bar graph indicates the detection distance for the older group is significantly shorter than the detection distances of both the young and middle age groups. Back to Figure 30.

Figure 31. Bar graph. Mean detection values for each VES for each of the three object groups. The graph is titled “VES by Object Group Interaction.” The Y-axis indicates detection distance in feet. The X-axis indicates the six VESs evaluated in the study. There are three bars for each VES, indicating the object group (obstacle, pedestrian, and retroreflective). Standard error bars are also provided for each graph bar. Detection distances for the obstacle group range from 105 feet (NIR 2) to 212 feet (FIR). Detection distances for the pedestrian group range from 176 feet (HID 2) to 681 feet (FIR). Detection distances for the retroreflective group range from 1,057 feet (FIR) to 1,962 feet (NIR 1). Standard error bars within each set of object groups are generally comparable, with the FIR detection of obstacles and pedestrians producing a slightly larger standard error than other headlamp systems when detecting obstacles and pedestrians. Back to Figure 31.

Figure 32. Bar graph. Mean recognition distances for each VES for each of the three object groups. The graph is titled “VES by Object Group Interaction.” The Y-axis indicates recognition distance in feet. The X-axis indicates the six VESs evaluated in the study. There are three bars for each VES, indicating the object group (obstacle, pedestrian, and retroreflective). Standard error bars are also provided for each graph bar. Recognition distances for the obstacle group range from 101 feet (NIR 2) to 153 feet (FIR). Recognition distances for the pedestrian group range from 169 feet (HID 2) to 582 feet (FIR). Recognition distances for the retroreflective group range from 984 feet (FIR) to 1,531 feet (HLB). Standard error bars for each set of object groups are generally comparable, with the FIR recognition of obstacles and pedestrians producing a slightly larger standard error than other headlamp systems when recognizing obstacles and pedestrians. Back to Figure 32.

Figure 33. Bar graph. Mean detection distances for the age main effect for the obstacle group. The graph is titled “Detection Distances for the Main Effect of Age for Obstacles.” The Y-axis indicates mean distance in feet. The X-axis indicates age category (young, middle, and older), and there is one bar for each. Letters above each bar note the groupings for the means (means with the same letter are not significantly different) based on the Student-Newman-Keuls results. The overall detection distance for the young group is 165 feet, for the middle group it is 159 feet, and for the older group it is 110 feet. Detection distance for the older group is significantly shorter than the detection distances of both the young and middle age groups. Back to Figure 33.

Figure 34. Bar graph. Tire and dog mean detection and recognition distances by VES. The graph is titled “Tire and Dog.” The Y-axis indicates mean distance in feet. The X-axis indicates the six VESs evaluated in the study. The left half of the graph presents data for detection and recognition of the tire (with two bars for each VES, one for detection and one for recognition), and the right half of the graph presents data for detection and recognition of the dog (also with detection and recognition bars for each VES). Standard error bars are also provided for each graph bar. Letters above each bar note the groupings for the means (means with the same letter are not significantly different) based on the Student-Newman-Keuls results. Capital letters indicate detection groupings, and lowercase letters indicate recognition groupings. The range of detection distances for the tire is from 141 feet (NIR 2) to 186 feet (HLB). The range of recognition distances for the tire is from 139 feet (NIR 2) to 166 feet (HLB). Standard error bars for detection of the tire are smallest for the NIR 2 and largest for the HLB. Standard error bars for recognition of the tire are smallest for the NIR 2 and fairly comparable between the remaining VESs. There are no significantly different distances between any of the VESs for detection and recognition of the tire. The range of detection distances for the dog is from 70 feet (NIR 2) to 259 feet (FIR). The range of recognition distances for the dog is from 63 feet (NIR 2) to 156 feet (FIR). Standard error bars for detection and recognition of the dog are larger for the FIR than for the other VESs. The mean detection distance of the dog for FIR is significantly higher than corresponding distances for the other VESs. The mean recognition distance of the dog for FIR is significantly higher than the corresponding distance for the NIR 2. Back to Figure 34.

Figure 35. Bar graph. Mean detection distances for the Age by VES interaction for pedestrian scenarios. The graph is titled “Age by VES Interaction for Pedestrian Scenarios.” The Y-axis indicates detection distance in feet. The X-axis indicates the six VESs evaluated in the study. There are three bars for each VES, indicating the age group (young, middle, and older). Standard error bars are also provided for each graph bar. Detection distances for the young group range from 205 feet (HID 2) to 877 feet (FIR). Detection distances for the middle group range from 189 feet (HID 2) to 706 feet (FIR). Detection distances for the older group range from 132 feet (HID 2) to 561 feet (NIR 1). Standard error bars for each set of object groups are generally comparable, with the FIR detection for all ages producing a slightly larger standard error than other headlamp systems. Back to Figure 35.

Figure 36. Bar graph. Mean detection and recognition distances for pedestrian in denim on straight—left and right side. The graph is titled “Pedestrian, Denim Clothing Left Side and Right Side.” The Y-axis indicates mean distance in feet. The X-axis indicates the six VESs evaluated in the study. The left half of the graph presents data for detection and recognition of the BlueLF (Blue Left) object (there are two bars for each VES, one for detection and one for recognition), and the right half of the graph presents data for detection and recognition of the BlueRT (Blue Right) object (also with detection and recognition bars for each VES). Standard error bars are also provided for each graph bar. Letters above each bar note the groupings for the means (means with the same letter are not significantly different) based on the Student-Newman-Keuls results. Capital letters indicate detection groupings, and lowercase letters indicate recognition groupings. A note is included stating that the FIR means may be reduced due to limited sight distance. The range of detection distances for the BlueLF is from 132 feet (HID 2) to 851 feet (FIR). The range of recognition distances for the BlueLF is from 129 feet (HID 2) to 774 feet (FIR). The standard error bars for detection and recognition of the BlueLF are smallest for HID 2 means and largest for FIR means. The mean detection distance of the BlueLF for FIR is significantly higher than the corresponding distances for all other VESs. The mean detection distance of the BlueLF for NIR 1 is significantly higher than corresponding distances for NIR 2, HLB, HID 1, and HID 2. The mean detection distances of the BlueLF for NIR 2 and HLB are significantly higher than corresponding distances for HID 1 and HID 2. The mean recognition distances of the BlueLF for FIR and NIR 1 are significantly higher than corresponding distances for the other VESs. The mean recognition distances of the BlueLF for NIR 2 and HLB are significantly higher than corresponding distances for HID 1 and HID 2. The range of detection distances for the BlueRT is from 268 feet (HID 2) to 894 feet (FIR). The range of recognition distances for the BlueRT is from 253 feet (HID 2) to 745 feet (FIR). The standard error bars for detection and recognition of the BlueRT are smallest for HID 2 means and largest for FIR means. The mean detection distances of the BlueRT for FIR and NIR 1 are significantly higher than corresponding distances for the other VESs. The mean detection distances of the BlueRT for NIR 2, HLB, and HID 1 are significantly higher than the corresponding distance for HID 2. The mean recognition distances of the BlueRT for FIR and NIR 1 are significantly higher than the corresponding distances for the other VESs. The mean recognition distance of the BlueRT for HLB is significantly higher than corresponding distances for NIR 2 and HID 2. The mean recognition distances of the BlueRT for HID 1 and NIR 2 are significantly higher than the corresponding distance for HID 2. Back to Figure 36.

Figure 37. Bar graph. Mean detection and recognition distances for pedestrian in black on straight—left and right side. The graph is titled “Pedestrian, Black Clothing Left Side and Right Side.” The Y-axis indicates mean distance in feet. The X-axis indicates the six VESs evaluated in the study. The left half of the graph presents data for detection and recognition of the BlackLF (Black Left) object (there are two bars for each VES, one for detection and one for recognition), and the right half of the graph presents data for detection and recognition of the BlackRT (Black Right) object (also with detection and recognition bars for each VES). Standard error bars are also provided for each graph bar. Letters above each bar note the groupings for the means (means with the same letter are not significantly different) based on the Student-Newman-Keuls results. Capital letters indicate detection groupings, and lowercase letters indicate recognition groupings. The range of detection distances for the BlackLF is from 90 feet (HID 2) to 579 feet (FIR). The range of recognition distances for the BlackLF is from 86 feet (HID 2) to 533 feet (FIR). The standard error bars for detection and recognition of the BlackLF are smallest for HID 2 means and largest for FIR means. The mean detection distance of the BlackLF for FIR is significantly higher than the corresponding distances for all other VESs. The mean detection distance of the BlackLF for NIR 1 is significantly higher than corresponding distances for NIR 2, HLB, HID 1, and HID 2. The mean detection distance of the BlackLF for HLB is significantly higher than corresponding distances for HID 1 and HID 2. The mean recognition distances of the BlackLF for FIR and NIR 1 are significantly higher than corresponding distances for the other VESs. The mean recognition distance of the BlackLF for HLB is significantly higher than corresponding distances for HID 1 and HID 2. The range of detection distances for the BlackRT is from 140 feet (HID 2) to 621 feet (FIR). The range of recognition distances for the BlackRT is from 136 feet (HID 2) to 560 feet (FIR). The standard error bars for detection and recognition of the BlackRT are smallest for HID 2 means and largest for FIR means. The mean detection distances of BlackRT for FIR and NIR 1 are significantly higher than corresponding distances for the other VESs. The mean detection distances of BlackRT for NIR 2, HLB, and HID 1 are significantly higher than the corresponding distance for HID 2. The mean recognition distances of BlackRT for FIR and NIR 1 are significantly higher than the corresponding distances for the other VESs. The mean recognition distances of BlackRT for NIR 2, HLB, and HID 1 are significantly higher than the corresponding distance for HID 2. Back to Figure 37.

Figure 38. Bar graph. Mean detection distances for bloom scenario, left and right side. The graph is titled “Bloom Scenario Pedestrian Left and Right.” The Y-axis indicates mean distance in feet. The X-axis indicates the six VESs evaluated in the study. The left half of the graph presents data for detection and recognition of the BloomLF (Bloom Left) object (there are two bars for each VES, one for detection and one for recognition), and the right half of the graph presents data for detection and recognition of the BloomRT (Bloom Right) object (also with detection and recognition bars for each VES). Standard error bars are also provided for each graph bar. Letters above each bar note the groupings for the means (means with the same letter are not significantly different) based on the Student-Newman-Keuls results. Capital letters indicate detection groupings, and lowercase letters indicate recognition groupings. For the BloomLF object, a note is included stating that the FIR means may be reduced due to limited sight distance. The range of detection distances for the BloomLF is from 85 feet (HID 2) to 898 feet (FIR). The range of recognition distances for the BloomLF is from 84 feet (HID 2) to 881 feet (FIR). The standard error bars for detection and recognition of the BloomLF are smallest for HID 1 and HID 2 means and largest for FIR means. The mean detection distance of the BloomLF for FIR is significantly higher than the corresponding distances for all other VESs. The mean detection distance of the BloomLF for NIR 1 is significantly higher than the corresponding distances for NIR 2, HLB, HID 1, and HID 2. The mean detection distance of the BloomLF for NIR 2 is significantly higher than the corresponding distance for HID 2. The mean recognition distance of the BloomLF for FIR is significantly higher than corresponding distances for the other VESs. The mean recognition distance of the BloomLF for NIR 1 is significantly higher than corresponding distances for NIR 2, HLB, HID 1 and HID 2. The mean recognition distance of the BloomLF for NIR 2 is significantly higher than the corresponding distance for HID 2. The range of detection distances for the BloomRT is from 182 feet (HID 2) to 567 feet (FIR). The range of recognition distances for the BloomRT is from 177 feet (HID 2) to 532 feet (FIR). The standard error bars for detection and recognition of the BloomRT are smallest for HID 2 means and largest for FIR means. The mean detection distances of the BloomRT for FIR and NIR 1 are significantly higher than corresponding distances for the other VESs. The mean detection distances of the BloomRT for NIR 2, HLB, and HID 1 are significantly higher than the corresponding distance for HID 2. The mean recognition distance of the BloomRT for FIR is significantly higher than the corresponding distances for NIR 2, HLB, HID 1, and HID 2. The mean recognition distance of the BloomRT for NIR 1 is significantly higher than the corresponding distances for NIR 2, HID 1, and HID 2. The mean recognition distances of the BloomRT for NIR 2, HLB, and HID 1 are significantly higher than the corresponding distance for HID 2.
Back to Figure 38.

Figure 39. Bar graph. Mean detection and recognition distances for pedestrian far off axis, left and right side. The graph is titled “Pedestrians 31 feet Off Axis Left Side and Right Side.” The Y-axis indicates mean distance in feet. The X-axis indicates the six VESs evaluated in the study. The left half of the graph presents data for detection and recognition of the FOALT (Far Off Axis Left) object (there are two bars for each VES, one for detection and one for recognition), and the right half of the graph presents data for detection and recognition of the FOART (Far Off Axis Right) object (also with detection and recognition bars for each VES). Standard error bars are also provided for each graph bar. Letters above each bar note the groupings for the means (means with the same letter are not significantly different) based on the Student-Newman-Keuls results. Capital letters indicate detection groupings, and lowercase letters indicate recognition groupings. The range of detection distances for the FOALT is from 168 feet (HID 2) to 865 feet (FIR). The range of recognition distances for the FOALT is from 167 feet (HID 2) to 685 feet (FIR). The standard error bars for detection and recognition of the FOALT are smallest for HID 2 means and largest for FIR means. The mean detection distances of the FOALT for FIR and NIR 1 are significantly higher than the corresponding distances for all other VESs. The mean detection distance of the FOALT for HLB is significantly higher than the corresponding distance for HID 2. The mean recognition distances of the FOALT for FIR and NIR 1 are significantly higher than corresponding distances for the other VESs. The mean recognition distances of the FOALT for HLB and HID 1 are significantly higher than the corresponding distance for HID 2. The range of detection distances for the FOART is from 89 feet (HID 2) to 889 feet (FIR). The range of recognition distances for the FOART is from 87 feet (NIR 2) to 680 feet (FIR). The standard error bars for detection and recognition of the FOART are smallest for HID 2 means and largest for FIR means. The mean detection distance of FOART for FIR is significantly higher than corresponding distances for the other VESs. The mean detection distance of FOART for NIR 1 is significantly higher than the corresponding distances for NIR 2, HLB, HID 1, and HID 2. The mean recognition distance of FOART for FIR is significantly higher than the corresponding distances for the other VESs. The mean recognition distance of FOART for NIR 1 is significantly higher than the corresponding distances for NIR 2 and HID 2. Back to Figure 39.

Figure 40. Bar graph. Mean detection and recognition distances for pedestrian in denim in right turn, left and right side. The graph is titled “Pedestrians in Right Turn (1,250-meter radius) Left Side and Right Side.” The Y-axis indicates mean distance in feet. The X-axis indicates the six VESs evaluated in the study. The left half of the graph presents data for detection and recognition of the RTtrnLF (Right Turn Left) object (there are two bars for each VES, one for detection and one for recognition), and the right half of the graph presents data for detection and recognition of the RTtrnRT (Right Turn Right) object (also with detection and recognition bars for each VES). Standard error bars are also provided for each graph bar. Letters above each bar note the groupings for the means (means with the same letter are not significantly different) based on the Student-Newman-Keuls results. Capital letters indicate detection groupings, and lowercase letters indicate recognition groupings. The range of detection distances for the RTtrnLF is from 319 feet (HID 2) to 698 feet (FIR). The range of recognition distances for the RTtrnLF is from 302 feet (HID 2) to 624 feet (FIR). The standard error bars for detection and recognition of the RTtrnLF are smallest for HLB means and largest for FIR means. The mean detection distance of the RTtrnLF for FIR is significantly higher than the corresponding distances for all other VESs. The mean detection distance of the RTtrnLF for NIR 1 is significantly higher than corresponding distances for NIR 2 and HID 2. The mean detection distances of the RTtrnLF for HLB and HID 1 are significantly higher than corresponding distance for HID 2. The mean recognition distance of the RTtrnLF for FIR is significantly higher than corresponding distances for NIR 2, HID 1, and HID 2. The mean recognition distances of the RTtrnLF for NIR 1, HLB, and HID 1 are significantly higher than the corresponding distance for HID 2. The range of detection distances for the RTtrnRT is from 264 feet (HID 2) to 440 feet (NIR 1). The range of recognition distances for the RTtrnRT is from 255 feet (HID 2) to 425 feet (NIR 1). The standard error bars for detection and recognition of the RTtrnRT are a bit larger for the FIR and NIR 1 means, and those of the remaining VESs are comparable to each other. The mean detection and recognition distances of RTtrnRT for FIR, NIR 1, HLB, and HID 1 are significantly higher than corresponding distances for NIR 2 and HID 2. Back to Figure 40.

Figure 41. Bar graph. Mean detection and recognition distances for pedestrian in denim in left turn, left and right side (1 ft = 0.305 m). The graph is titled “Pedestrians in Left Turn (1,250-meter radius) Left Side and Right Side.” The Y-axis indicates mean distance in feet. The X-axis indicates the six VESs evaluated in the study. The left half of the graph presents data for detection and recognition of the LFtrnLF (Left Turn Left) object (there are two bars for each VES, one for detection and one for recognition), and the right half of the graph presents data for detection and recognition of the LFtrnRT (Left Turn Right) object (also with detection and recognition bars for each VES). Standard error bars are also provided for each graph bar. Letters above each bar note the groupings for the means (means with the same letter are not significantly different) based on the Student-Newman-Keuls results. Capital letters indicate detection groupings, and lowercase letters indicate recognition groupings. The range of detection distances for the LFtrnLF is from 98 feet (FIR) to 500 feet (NIR 1). The range of recognition distances for the LFtrnLF is from 95 feet (FIR) to 487 feet (NIR 1). The standard error bars for detection and recognition of the LFtrnLF are smallest for HID 2 means and largest for NIR 1 and NIR 2 means. The mean detection distances of the LFtrnLF for all VESs are significantly different in the following order (from greatest to least): NIR 1, HLB, HID 1, NIR 2, HID 2, and FIR. The mean recognition distances of the LFtrnLF for all VESs are significantly different in the same order as detection with the exception of the NIR 2 and HID 2, which are in the same order numerically, but do not have significantly different recognition means from each other. The range of detection distances for the LFtrnRT is from 204 feet (HID 2) to 768 feet (FIR). The range of recognition distances for the LFtrnRT is from 186 feet (HID 2) to 591 feet (NIR 1). The standard error bars for detection and recognition of the LFtrnRT are smallest for HLB, HID 1, and HID 2 means and largest for FIR means. The mean detection distances of LFtrnRT for FIR and NIR 1 are significantly higher than the corresponding distances for the remaining VESs. The mean detection distances of LFtrnRT for NIR 2 and HLB are significantly higher than the corresponding distance for HID 2. The mean recognition distance of LFtrnRT for NIR 1 is significantly higher than the corresponding distances for the remaining VESs. The mean recognition distance of LFtrnRT for FIR is significantly higher than the corresponding distances for HID 1 and HID 2. The mean recognition distances of LFtrnRT for NIR 2 and HLB are significantly higher than the corresponding distance for HID 2. Back to Figure 41.

Figure 42. Bar graph. Mean detection and recognition distances for retroreflective object group by VES. The graph is titled “Retroreflective Object Detection and Recognition Distances by VES.” The Y-axis indicates mean distance in feet. The X-axis indicates the six VESs evaluated in the study. There are two bars for each VES, one for detection and one for recognition. Letters above each bar note the groupings for the means (means with the same letter are not significantly different) based on the Student-Newman-Keuls results. Capital letters indicate detection groupings, and lowercase letters indicate recognition groupings. The range of detection distances for the retroreflective objects is from 1,057 feet (FIR) to 1,962 feet (NIR 1). The range of recognition distances for the retroreflective objects is from 984 feet (FIR) to 1,531 feet (HLB). The mean detection distances of the retroreflective objects for the NIR 1, HLB, and HID 1 are significantly higher than the corresponding distances for the remaining VESs. The mean detection distances of the retroreflective objects for the remaining VESs are also significantly different from each other in the following order (from greatest to least distance): NIR 2, HID 2, and FIR. The mean recognition distances of the retroreflective objects for the NIR 1, HLB, and HID 1 are significantly higher than the corresponding distances for the remaining VESs. The mean recognition distances of the retroreflective objects for the NIR 2 and HID 2 are significantly higher than the corresponding distance for the FIR. Back to Figure 42.

Figure 43. Bar graph. Mean detection distances for the VES by Object interaction for retroreflective group. The graph is titled “Detection Distances for the VES by Retroreflective Object Interaction.” The Y-axis indicates mean distance in feet. The X-axis indicates the six VESs evaluated in the study. There are three bars for each VES: one for Arrow, one for RRPM, and one for Sign. Standard error bars are also provided for each graph bar. The approximate range of detection distances for the arrow is from 200 feet (FIR) to 300 feet (HLB). Standard error bars are very small for NIR 2 and HID 2, and only slightly larger for the remaining VESs. The approximate range of detection distances for the RRPM is from just over 500 feet (FIR) to 1,800 feet (NIR 1). Standard error bars are smallest for FIR and HID 2, and larger (all similar) for the remaining VESs. The approximate range of detection distances for the sign is from 1,800 feet (FIR) to 2,900 feet (NIR 1). Standard error bars are smallest for NIR 1 and largest for HID 2. Back to Figure 43.

Figure 44. Bar graph. Mean recognition distances for VES by Object interaction for retroreflective group. The graph is titled “Recognition Distances for the VES by Retroreflective Object Interaction.” The Y-axis indicates mean distance in feet. The X-axis indicates the six VESs evaluated in the study. There are three bars for each VES, one for Arrow, one for RRPM, and one for Sign. Standard error bars are also provided for each graph bar. The approximate range of recognition distances for the arrow is from 160 feet (FIR) to 260 feet (HLB). The standard error bar is very small for NIR 2, and only slightly larger for the remaining VESs. The approximate range of recognition distances for the RRPM is from just under 500 feet (FIR) to 1,400 feet (HLB). Standard error bars are smallest for FIR and HID 2 and largest for the remaining VESs. The approximate range of recognition distances for the sign is from 1,650 feet (FIR) to 2,300 feet (NIR 1). Standard error bars are fairly comparable between all VESs. Back to Figure 44.

Figure 45. Bar graph. Arrow detection and recognition distances by VES. The graph is titled “Arrow.” The Y-axis indicates mean distance in feet. The X-axis indicates the six VESs evaluated in the study. There are two bars for each VES, one for detection and one for recognition. Standard error bars are also provided for each graph bar. Letters above each bar note the groupings for the means (means with the same letter are not significantly different) based on the Student-Newman-Keuls results. Capital letters indicate detection groupings, and lowercase letters indicate recognition groupings. The range of detection distances for the arrow is from 174 feet (FIR) to 295 feet (HLB). The range of recognition distances for the arrow is from 158 feet (FIR) to 261 feet (HLB). The standard error bars for detection and recognition of the arrow are smallest for NIR 2 means and largest for HID 1 means. The mean detection distance of the arrow for HLB is significantly higher than corresponding distances for the remaining VESs. The mean detection distances of the arrow for NIR 1 and HID 1 are significantly higher than corresponding distances for FIR and NIR 2. The mean recognition distances of the arrow for NIR 1, HLB, and HID 1 are significantly higher than corresponding distances for the other VESs. The mean recognition distance of the arrow for HID 2 is significantly higher than the corresponding distance for FIR. Back to Figure 45.

Figure 46. Bar graph. Raised retroreflective pavement marker (RRPM) detection and recognition distances by VES. The graph is titled “RRPM.” The Y-axis indicates mean distance in feet. The X-axis indicates the six VESs evaluated in the study. There are two bars for each VES, one for detection and one for recognition. Standard error bars are also provided for each graph bar. Letters above each bar note the groupings for the means (means with the same letter are not significantly different) based on the Student-Newman-Keuls results. Capital letters indicate detection groupings and lowercase letters indicate recognition groupings. The range of detection distances for the RRPM is from 527 feet (FIR) to 1,777 feet (NIR 1). The range of recognition distances for the RRPM is from 472 feet (FIR) to 1,367 feet (HLB). The standard error bars for detection and recognition of the Arrow are smallest for FIR and HID 2 means and largest for the remaining means. The mean detection distance of the RRPM for NIR 1 is significantly higher than the corresponding distances for FIR, NIR 2, HLB, and HID 2. The mean detection distances of the RRPM for HLB and HID 1 are significantly higher than corresponding distances for FIR, NIR 2, and HID 2. The mean detection distance of the RRPM for NIR 2 is significantly higher than the corresponding distance for FIR. The mean recognition distances of the RRPM for HLB and HID 1 are significantly higher than corresponding distances for the other VESs. The mean recognition distance of the RRPM for NIR 1 is significantly higher than the corresponding distance for FIR. Back to Figure 46.

Figure 47. Bar graph. Sign detection and recognition distances by VES. The graph is titled “Signs.” The Y-axis indicates mean distance in feet. The X-axis indicates the six VESs evaluated in the study. There are two bars for each VES, one for detection (“I see something ahead”) and one for recognition (“It’s a sign”). Standard error bars are also provided for each graph bar. Letters above each bar note the groupings for the means (means with the same letter are not significantly different) based on the Student-Newman-Keuls results. Capital letters indicate detection groupings and lowercase letters indicate recognition groupings. The range of detection distances for the signs is from 1,764 feet (FIR) to 2,909 feet (NIR 1). The range of recognition distances for the signs is from 1,654 feet (FIR) to 2,313 feet (NIR 1). The standard error bar for detection of the signs is smallest for NIR 1 means, but all bars are fairly comparable. Standard error bars for recognition of the signs are also fairly comparable, with those for FIR and NIR 2 slightly smaller than the remaining VESs. The mean detection distances of the signs for NIR 1, NIR 2, HLB, and HID 1 are significantly higher than the corresponding distances for HID 2 and FIR. The mean detection distance of the signs for HID 2 is significantly higher than the corresponding distance for FIR. The mean recognition distance of the signs for NIR 1, NIR 2, HLB, and HID 1 are significantly higher than the corresponding distance for FIR.
Back to Figure 47.

Figure 48. Bar graph. Sign recognition distances of stop versus yield sign by VES. The graph is titled “Recognition of Stop vs. Yield.” The Y-axis indicates mean distance in feet. The X-axis indicates the six VESs evaluated in the study. Standard error bars are also provided for each graph bar. Letters above each bar note the groupings for the means (means with the same letter are not significantly different) based on the Student-Newman-Keuls results. The range of recognition distances for the Signs is from 761 feet (HID 2) to 982 feet (HLB). The standard error bars for recognition are all fairly comparable between VESs. There are no significant differences between the mean recognition distances of the Signs for any of the VESs. Back to Figure 48.

Figure 49. Bar graph. Mean distances at which speed limit signs were read. The graph is titled “Recognition of Speed Limit.” The Y-axis indicates mean distance in feet. The X-axis indicates the six VESs evaluated in the study. Standard error bars are also provided for each graph bar. Letters above each bar note the groupings for the means (means with the same letter are not significantly different) based on the Student-Newman-Keuls results. The range of recognition distances for the signs is from 356 feet (HID 2) to 428 feet (HID 1). The standard error bars for recognition are all fairly comparable between VESs. There are no significant differences between the mean recognition distances of the signs for any of the VESs. Back to Figure 49.

Figure 50. Bar graph. Mean distance at which speed limit signs were read by each age group. The graph is titled “Recognition of Speed Limit by Age.” The Y-axis indicates mean distance in feet. The X-axis indicates age category (Young, Middle, Older), and there is one bar for each age category. Standard error bars are also provided for each graph bar. Letters above each bar note the groupings for the means (means with the same letter are not significantly different) based on the Student-Newman-Keuls results. The range of mean distances for reading speed limit signs is from 337 feet (Older age group) to 498 feet (young age group). The standard error bar is largest for the middle age group and smallest for the older age group. There are no significant differences between the mean distances for reading the signs for any of the age groups.
Back to Figure 50.

Figure 51. Bar graph. Mean subjective ratings by VES for Statement 1: This vision enhancement system allowed me to detect objects sooner than my regular headlights. The graph is titled “Statement 1: This VES allowed me to DETECT objects sooner than my regular headlights (1–7).” The Y-axis indicates the six VESs evaluated in the study. The X-axis shows the average (mean) rating for the statement, starting on the left at 1 (“Strongly Agree”) and ending on the right at 7 (“Strongly Disagree”). A lower rating indicates a more desirable system. Standard error bars are also provided for each graph bar. Letters to the right of each bar note the groupings for the means (means with the same letter are not significantly different) based on the Student-Newman-Keuls results. The range of mean ratings is from 1.2 (NIR 1) to 3.7 (HID 2). The standard error bar is smallest for the NIR 1 mean and fairly comparable among the remaining VESs. The mean rating for NIR 1 is significantly lower than the mean ratings for all other VESs. There are no significant differences between the remaining five VESs. Back to Figure 51.

Figure 52. Bar graph. Mean subjective ratings by VES for Statement 2: This vision enhancement system allowed me to identify objects sooner than my regular headlights. The graph is titled “Statement 2: This VES allowed me to IDENTIFY objects sooner than my regular headlights (1–7).” The Y-axis indicates the six VESs evaluated in the study. The X-axis shows the average (mean) rating for the statement, starting on the left at 1 (“Strongly Agree”) and ending on the right at 7 (“Strongly Disagree”). A lower rating indicates a more desirable system. Standard error bars are also provided for each graph bar. Letters to the right of each bar note the groupings for the means (means with the same letter are not significantly different) based on the Student-Newman-Keuls results. The range of mean ratings is from 1.7 (NIR 1) to 3.8 (HID 2). The standard error bar is smallest for the NIR 1 mean and largest for the HID 2 mean. The mean rating for NIR 1 is significantly lower than the mean ratings for HLB and HID 2. The mean ratings for FIR, NIR 2, HLB, and HID 1 are significantly lower than the mean rating for HID 2. Back to Figure 52.

Figure 53. Bar graph. Mean subjective ratings by VES for Statement 3: This vision enhancement system helped me to stay on the road (not go over the lines) better than my regular headlights. The graph is titled “Statement 3: This VES helped me to stay on the road (not go over the lines) better than my regular headlights (1–7).” The Y-axis indicates the six VESs evaluated in the study. The X-axis shows the average (mean) rating for the statement, starting on the left at 1 (“Strongly Agree”) and ending on the right at 7 (“Strongly Disagree”). A lower rating indicates a more desirable system. Standard error bars are also provided for each graph bar. Letters to the right of each bar note the groupings for the means (means with the same letter are not significantly different) based on the Student-Newman-Keuls results. The range of mean ratings is from 3.4 (HID 1) to 4.7 (FIR). The standard error bar is smallest for the HLB mean and largest for the FIR mean. The mean rating for HID 1 is significantly lower than the mean ratings for FIR and NIR 2. The mean rating for HLB is significantly lower than the mean rating for FIR. Back to Figure 53.

Figure 54. Bar graph. Mean subjective ratings by VES for Statement 4: This vision enhancement system allowed me to see which direction the road was heading (i.e., left, right, straight) beyond my regular headlights. The graph is titled “Statement 4: This VES allowed me to see which direction the road was heading (i.e., left; right; straight) beyond my regular headlights (1–7).” The Y-axis indicates the six VESs evaluated in the study. The X-axis shows the average (mean) rating for the statement, starting on the left at 1 (“Strongly Agree”) and ending on the right at 7 (“Strongly Disagree”). A lower rating indicates a more desirable system. Standard error bars are also provided for each graph bar. Letters to the right of each bar note the groupings for the means (means with the same letter are not significantly different) based on the Student-Newman-Keuls results. The range of mean ratings is from 2.3 (NIR 1) to 3.9 (HID 2). The standard error bars are smallest for the NIR 1, HLB, and HID 1 means and largest for the FIR mean. The mean rating for NIR 1 is significantly lower than the mean ratings for FIR, NIR 2, and HID 2. The mean ratings for HLB and HID 1 are significantly lower than the mean rating for HID 2. Back to Figure 54.

Figure 55. Bar graph. Mean subjective ratings by VES for Statement 5: This vision enhancement system did not cause me any more visual discomfort than my regular headlights. The graph is titled “Statement 5: This VES did not cause me any more visual discomfort than my regular headlights (1–7).” The Y-axis indicates the six VESs evaluated in the study. The X-axis shows the average (mean) rating for the statement, starting on the left at 1 (“Strongly Agree”) and ending on the right at 7 (“Strongly Disagree”). A lower rating indicates a more desirable system. Standard error bars are also provided for each graph bar. Letters to the right of each bar note the groupings for the means (means with the same letter are not significantly different) based on the Student-Newman-Keuls results. The range of mean ratings is from 1.7 (HID 1) to 2.9 (NIR 2). The standard error bars are smallest for the HLB and HID 1 means and fairly comparable among the remaining VESs. The mean rating for HID 1 is significantly lower than the mean rating for NIR 2. There are no other significant differences between other VESs. Back to Figure 55.

Figure 56. Bar graph. Mean subjective ratings by VES for Statement 6: This vision enhancement system allowed me to read signs beside the road sooner than my regular headlights. The graph is titled “Statement 6: This VES allowed me to read signs beside the road sooner than my regular headlights (1–7).” The Y-axis indicates the six VESs evaluated in the study. The X-axis shows the average (mean) rating for the statement, starting on the left at 1 (“Strongly Agree”) and ending on the right at 7 (“Strongly Disagree”). A lower rating indicates a more desirable system. Standard error bars are also provided for each graph bar. Letters to the right of each bar note the groupings for the means (means with the same letter are not significantly different) based on the Student-Newman-Keuls results. The range of mean ratings is from 3.1 (HID 1) to 5.0 (NIR 2). The standard error bar is smallest for the HID 1 mean and largest for the FIR and NIR 2 means. The mean ratings for HLB, HID 1, and HID 2 are significantly lower than the mean ratings for FIR, NIR 1, and NIR 2. Back to Figure 56.

Figure 57. Bar graph. Mean subjective ratings by VES for Statement 7: This vision enhancement system makes me feel safer when driving on the roadways at night than my regular headlights. The graph is titled “Statement 7: This VES makes me feel safer when driving on the roadways at night than my regular headlights (1–7).” The Y-axis indicates the six VESs evaluated in the study. The X-axis shows the average (mean) rating for the statement, starting on the left at 1 (“Strongly Agree”) and ending on the right at 7 (“Strongly Disagree”). A lower rating indicates a more desirable system. Standard error bars are also provided for each graph bar. Letters to the right of each bar note the groupings for the means (means with the same letter are not significantly different) based on the Student-Newman-Keuls results. The range of mean ratings is from 2.2 (NIR 1) to 3.7 (HID 2). The standard error bars are smallest for the HLB and HID 1 means and fairly comparable among the remaining VESs. The mean rating for NIR 1 is significantly lower than the mean rating for HID 2. There are no other significant differences between other VESs. Back to Figure 57.

Figure 58. Bar graph. Mean subjective ratings by VES for Statement 8: This is a better vision enhancement system than my regular headlights. The graph is titled “Statement 8: This is a better VES than my regular headlights (1–7).” The Y-axis indicates the six VESs evaluated in the study. The X-axis shows the average (mean) rating for the statement, starting on the left at 1 (“Strongly Agree”) and ending on the right at 7 (“Strongly Disagree”). A lower rating indicates a more desirable system. Standard error bars are also provided for each graph bar. The range of mean ratings is from 2.0 (NIR 1) to 3.4 (HID 2). The standard error bars are fairly comparable for all VESs. There were no significant differences between mean ratings for any of the VESs. Back to Figure 58.

Figure 59. Equation. Braking distance approximation. d subscript BD equals V squared divided by the following: the sum of f and uppercase G, end of sum, that sum multiplied by lowercase g, multiplied by 2.
Back to Figure 59.

Figure 60. Equation. Distance for brake reaction time and braking distance. d equals the following sum: 2.5 multiplied by V, that product plus the quotient of V squared divided by the product of 2 multiplied by g multiplied by f. Back to Figure 60.

Figure 61. Diagram. Detection distance diagram key. This diagram depicts an overhead view of a roadway with the participant vehicle and various icons representing the objects used in the study. Two partially overlapping sections of road, one curving left and one going straight, are depicted. On the straight section of road are icons representing left and right pedestrians (in black, in blue, bloom, and far off axis), tire tread, dog, arrow, signs, and RRPMs. On the section of road curving to the left are icons representing left and right pedestrians (blue, along a 1,250-meter radius curve). A statement is included noting that right curve scenarios mirror left curve. There is also an expanded diagram of the bloom layout, which shows the left bloom scenario (the participant vehicle in the right lane facing a car in the left lane that has its headlamps on; standing by its rear wheels and facing the participant vehicle is a pedestrian on the left shoulder of the road) and the right bloom scenario (the participant vehicle in the right lane facing a car in the left lane that has its headlamps on; standing across from its rear wheels and facing the participant vehicle is a pedestrian on the right shoulder of the road). Back to Figure 61.

Figure 62. Diagram. HLB mean detection distances. This diagram depicts an overhead view of the participant vehicle on a roadway. Three partially overlapping sections of road, one curving left, one going straight, and one curving right, are depicted. The icons used to depict each object used in the study are pictured on the road at their appropriate locations along a measurement grid. The left side of the grid indicates the mean distances of detection using the HLB. The right side of the grid presents labels at the approximate stopping distances necessary for various speeds. The dog and the tire tread are at detection distances between 100 and 200 feet (requiring speeds less than about 25 to 35 miles per hour to accommodate necessary stopping distances). The bloom left pedestrian, left pedestrian in black, and arrow are at detection distances between 200 and 300 feet (requiring speeds less than about 35 to 45 miles per hour to accommodate necessary stopping distances). The left turn left pedestrian, bloom right pedestrian, right pedestrian in black, and far off axis right pedestrian are at detection distances between 300 and 400 feet (requiring speeds less than about 50 to 60 miles per hour to accommodate necessary stopping distances). The far off axis left pedestrian, left pedestrian in blue, left turn right pedestrian, right turn left pedestrian, and right turn right pedestrian are at detection distances between 400 and just over 500 feet (requiring speeds less than about 60 to 70 miles per hour to accommodate necessary stopping distances). The right pedestrian in blue is at a detection distance of about 600 feet (with adequate stopping distance at speeds above 70 miles per hour). Back to Figure 62.

Figure 63. Diagram. FIR mean detection distances. This diagram depicts an overhead view of the participant vehicle on a roadway. Three partially overlapping sections of road, one curving left, one going straight, and one curving right, are depicted. The icons used to depict each object used in the study are pictured on the road at their appropriate locations along a measurement grid. The left side of the grid indicates the mean distances of detection using the FIR. The right side of the grid presents labels at the approximate stopping distances necessary for various speeds. The left turn left pedestrian, arrow, and tire tread are at detection distances between 100 and 200 feet (requiring speeds less than about 25 to 35 miles per hour to accommodate necessary stopping distances). The dog is at a detection distance of about 260 feet (requiring speeds less than about 45 miles per hour to accommodate necessary stopping distances). The right turn right pedestrian is at a detection distance of about 440 feet (requiring speeds less than about 65 miles per hour to accommodate necessary stopping distances). The left pedestrian in black and bloom right pedestrian are at detection distances of about 550 to 600 feet (with adequate stopping distance at speeds up to a bit greater than 70 miles per hour). The right pedestrian in black, right turn left pedestrian, and left turn right pedestrian are at detection distances between 600 and 800 feet (with adequate stopping distance at speeds up to and greater than 70 miles per hour). The left pedestrian in blue, far off axis left pedestrian, bloom left pedestrian, right pedestrian in blue, and far off axis right pedestrian are at detection distances between 850 and 900 feet (with adequate stopping distance at speeds up to and well over 70 miles per hour). Back to Figure 63.

Figure 64. Diagram. NIR 1 mean detection distances. This diagram depicts an overhead view of the participant vehicle on a roadway. Three partially overlapping sections of road, one curving left, one going straight, and one curving right, are depicted. The icons used to depict each object used in the study are pictured on the road at their appropriate locations along a measurement grid. The left side of the grid indicates the mean distances of detection using the NIR 1. The right side of the grid presents labels at the approximate stopping distances necessary for various speeds. The dog and the tire tread are at detection distances between 100 and 200 feet (requiring speeds less than about 25 to 35 miles per hour to accommodate necessary stopping distances). The arrow is at a detection distance of about 250 feet (requiring speeds less than about 45 miles per hour to accommodate necessary stopping distances). The left turn left pedestrian, left pedestrian in black, bloom right pedestrian, and right turn right pedestrian are at detection distances between 400 and 500 feet (requiring speeds less than about 60 to 70 miles per hour to accommodate necessary stopping distances). The right turn left pedestrian, right pedestrian in black, and far off axis right pedestrian are at detection distances between 500 and 600 feet (with adequate stopping distance at speeds up to and a bit greater than 70 miles per hour). The bloom left pedestrian and left turn right pedestrian are at detection distances between 600 and 700 feet (with adequate stopping distance at speeds up to and greater than 70 miles per hour). The left pedestrian in blue, far off axis left pedestrian, and right pedestrian in blue are at detection distances between 700 and 800 feet (with adequate stopping distance at speeds up to and well over 70 miles per hour). Back to Figure 64.

Figure 65. Diagram. NIR 2 mean detection distances. This diagram depicts an overhead view of the participant vehicle on a roadway. Three partially overlapping sections of road, one curving left, one going straight, and one curving right, are depicted. The icons used to depict each object used in the study are pictured on the road at their appropriate locations along a measurement grid. The left side of the grid indicates the mean distances of detection using the NIR 2. The right side of the grid presents labels at the approximate stopping distances necessary for various speeds. The dog is at a detection distance of less than 100 feet (requiring speeds less than about 20 miles per hour to accommodate necessary stopping distances). The arrow, tire tread, and far off axis right pedestrian are at detection distances between 100 and 200 feet (requiring speeds less than about 25 to 35 miles per hour to accommodate necessary stopping distances). The left turn left pedestrian, left pedestrian in black, bloom left pedestrian, and right turn right pedestrian are at detection distances between 200 and 300 feet (requiring speeds less than about 35 to 50 miles per hour to accommodate necessary stopping distances). The far off axis left pedestrian, right turn left pedestrian, left turn right pedestrian, right pedestrian in black, and bloom right pedestrian are at detection distances between 300 and 400 feet (requiring speeds less than about 50 to 60 miles per hour to accommodate necessary stopping distances). The left pedestrian in blue and right pedestrian in blue are at detection distances between 400 and 500 feet (requiring speeds less than about 60 to 65 miles per hour to accommodate necessary stopping distances). Back to Figure 65.

Figure 66. Diagram. HID 1 mean detection distances. This diagram depicts an overhead view of the participant vehicle on a roadway. Three partially overlapping sections of road, one curving left, one going straight, and one curving right, are depicted. The icons used to depict each object used in the study are pictured on the road at their appropriate locations along a measurement grid. The left side of the grid indicates the mean distances of detection using the HID 1. The right side of the grid presents labels at the approximate stopping distances necessary for various speeds. The left pedestrian in black, bloom left pedestrian, dog, and tire tread are at detection distances between 100 and 200 feet (requiring speeds less than about 25 to 35 miles per hour to accommodate necessary stopping distances). The left turn left pedestrian, left pedestrian in blue, left turn right pedestrian, far off axis right pedestrian, and the arrow are at detection distances between 200 and 300 feet (requiring speeds less than about 35 to 45 miles per hour to accommodate necessary stopping distances). The far off axis left pedestrian, bloom right pedestrian, and right pedestrian in black are at detection distances between about 350 and 400 feet (requiring speeds less than about 55 to 60 miles per hour to accommodate necessary stopping distances). The right turn left pedestrian and right turn right pedestrian are at detection distances between 400 and 500 feet (requiring speeds less than about 60 to 65 miles per hour to accommodate necessary stopping distances). The right pedestrian in blue is at a detection distance of about 525 feet (with adequate stopping distance at speeds of up to about 70 miles per hour). Back to Figure 66.

Figure 67. Diagram. HID 2 mean detection distances. This diagram depicts an overhead view of the participant vehicle on a roadway. Three partially overlapping sections of road, one curving left, one going straight, and one curving right, are depicted. The icons used to depict each object used in the study are pictured on the road at their appropriate locations along a measurement grid. The left side of the grid indicates the mean distances of detection using the HID 2. The right side of the grid presents labels at the approximate stopping distances necessary for various speeds. The bloom left pedestrian, left pedestrian in black, far off axis right pedestrian, and the dog are at detection distances of less than 100 feet (requiring speeds less than about 20 miles per hour to accommodate necessary stopping distances). The left pedestrian in blue, left turn left pedestrian, far off axis left pedestrian, right pedestrian in black, bloom right pedestrian, and the tire tread are at detection distances between 100 and 200 feet (requiring speeds less than about 25 to 35 miles per hour to accommodate necessary stopping distances). The left turn right pedestrian, right pedestrian in blue, right turn right pedestrian, and the arrow are at detection distances between 200 and 300 feet (requiring speeds less than about 35 to 45 miles per hour to accommodate necessary stopping distances). The right turn left pedestrian is at a detection distance of about 325 feet (requiring speeds less than about 50 miles per hour to accommodate necessary stopping distances). Back to Figure 67.

Figure 68. Bar graph. Mean detection distances of pedestrians for older group with IR versus younger group with HLB. The graph is titled “Older Group with IR and HLB versus Younger Group with HLB.” The Y-axis indicates detection in feet. The X-axis indicates the objects used in the study. There are four bars for each object: Older with FIR, Older with NIR 1, Younger with HLB, and Older with HLB. Standard error bars are also provided for each graph bar. The approximate range of detection distances for the Older with FIR group is from 100 feet (left turn left pedestrian) to 700 feet (bloom left pedestrian). The standard error bars are smallest for the left turn left pedestrian, and largest for the right turn left pedestrian. The approximate range of detection distances for the Older with NIR 1 group is from just under 400 feet (left pedestrian in black) to around 950 feet (far off axis left pedestrian). Standard error bars are smallest for the bloom right and right turn right pedestrians and largest for the far off axis left pedestrian. The approximate range of recognition distances for the Younger with HLB group is from just under 200 feet (bloom left pedestrian) to just over 700 feet (right pedestrian in blue). Standard error bars are smallest for the left pedestrian in black, bloom right pedestrian, and left turn right pedestrian and largest for the far off axis left pedestrian. The approximate range of recognition distances for the Older with HLB group is from about 100 feet (bloom left pedestrian) to about 450 feet (right pedestrian in blue and right turn left pedestrian). Standard error bars are smallest for the bloom right pedestrians and left turn left pedestrians and largest for the far off axis left pedestrian.
Back to Figure 68.

Figure 69. Bar graph. Mean detection distances for VES by Object (people) interaction, turns only. The graph is titled “Detection Distances for VES by Object Interaction Turns Only.” The Y-axis indicates mean detection distance in feet. The X-axis indicates the objects used in the study (in turns only). There are six bars for each object, indicating the six VESs evaluated in the study. Standard error bars are also provided for each graph bar. The approximate range of detection distances for the FIR is from 100 feet (left turn left pedestrian) to around 770 feet (left turn right pedestrian). The standard error bars are smallest for the left turn left pedestrian and largest for the left turn right pedestrian. The approximate range of detection distances for the NIR 1 is from about 450 feet (right turn right pedestrian) to around 675 feet (left turn right pedestrian). Standard error bars are fairly comparable for all objects. The approximate range of recognition distances for the NIR 2 is from around 200 feet (left turn left pedestrian) to just under 400 feet (left turn right pedestrian). Standard error bars are smallest for the right turn right pedestrians and fairly comparable among the remaining objects. The approximate range of recognition distances for the HLB is from 350 feet (left turn left pedestrian) to 500 feet (right turn left pedestrian). Standard error bars are smallest for the left turn left and left turn right pedestrians and largest for the right turn right pedestrian. The approximate range of recognition distances for the HID 1 is from around 275 feet (left turn left pedestrian) to just over 450 feet (right turn left pedestrian). Standard error bars are smallest for the left turn right pedestrians and fairly comparable among all other objects. The approximate range of recognition distances for the HID 2 is from about 175 feet (left turn left pedestrian) to just over 300 feet (right turn left pedestrian). Standard error bars are smallest for left turn left and left turn right pedestrians and largest for right turn left pedestrians. Back to Figure 69.

Figure 70. Diagram. Comparison of 11.7-degree and 18-degree field of view. This diagram presents an overhead view of the 11.7-degree field of view scenario overlaid on the 18-degree field of view scenario for three overlapping segments of roadway: a straight segment and two 1,250-meter radius curves, left and right. The diagram indicates that the 11.7-degree (FIR/NIR 2) field of view headlamp pattern is much tighter than the 18-degree (NIR 1) field of view headlamp pattern. The 11.7-degree pattern barely covers the left side of the road on the left curve and extends slightly beyond the right side of the road on the right curve. The 18-degree pattern extends a bit beyond the left side of the road (left curve), and even more to the right side of the road (right curve). Back to Figure 70.

Figure 71. Bar graph. Detection distances for VES by Pedestrian Locations interaction, bloom scenarios only. The graph is titled “VES by Pedestrian Locations Interactions Bloom Scenarios.” The Y-axis indicates detection distance in feet. The X-axis indicates object (bloom left and bloom right). There are six bars for each object, indicating the six VESs evaluated in the study. Standard error bars are also provided for each graph bar. The detection distances for FIR are 898 feet (bloom left) and 567 feet (bloom right). The detection distances for NIR 1 are 635 feet (bloom left) and 495 feet (bloom right). The detection distances for NIR 2 are 290 feet (bloom left) and 307 feet (bloom right). The detection distances for HLB are 226 feet (bloom left) and 385 feet (bloom right). The detection distances for HID 1 are 136 feet (bloom left) and 348 feet (bloom right). The detection distances for HID 2 are 85 feet (bloom left) and 182 feet (bloom right). Standard error bars are smallest for HID 2 (left and right) and largest for FIR (left and right). Back to Figure 71.

Figure 72. Bar graph. Detection distances for VES by Pedestrian Scenario interactions: HLB versus HID 1. The graph is titled “VES by Pedestrian Scenario Interaction HLB and HID 1.” The Y-axis indicates detection distance in feet. The X-axis indicates object, including all pedestrian objects. There are two bars for each object, indicating HLB and HID 1. Standard error bars are also provided for each graph bar. The range of detection distance for the HLB is from 226 feet (bloom left) to 599 feet (right pedestrian in blue). The range of detection distances for HID 1 is from 115 feet (left pedestrian in black) to 517 feet (right pedestrian in blue). For every object except right turn right, the detection distance of the HLB is greater than that of the HID 1. Standard error bars are smallest for bloom left with HID 1 and largest for bloom left with HLB.
Back to Figure 72.

Figure 73. Line graph. Percent of detection distances insufficient for complete stop for pedestrian scenarios. The graph is titled “Pedestrian Scenario Trials Percentage of Detection Distances Insufficient for Complete Stop from Given Speed.” The Y-axis indicates percentage insufficient for complete stop. The X-axis indicates speed in miles per hour (miles per hour). Notes indicate that scenario trials and locations are not indicative of frequency of occurrences while driving and that complete stop is not necessarily required in real driving situations. The graph indicates that, for speeds of 25 to around 68 miles per hour, NIR 1 results in the lowest percentage insufficient for complete stop (from under 5 percent at 25 miles per hour to around 35 percent at 68 miles per hour). For speeds from about 68 to 70 miles per hour, FIR results in the lowest percentage insufficient for complete stop (from about 35 percent at 68 miles per hour to around 38 percent at 70 miles per hour). For HLB, the percentage insufficient for complete stop steadily increases from about 5 percent at 25 miles per hour to nearly 80 percent at 70 miles per hour. The percentages for NIR 2 and HID 1 are generally higher than NIR 1, FIR, and HLB. For HID 1, the percentage steadily increases from about 13 percent at 25 miles per hour to nearly 90 percent at 70 miles per hour. For NIR 2, the percentage steadily increases from about 20 percent at 25 miles per hour to about 83 percent at 70 miles per hour. The HID 2 clearly demonstrates the highest percentages insufficient for complete stop, from around 32 percent at 25 miles per hour to nearly 100 percent at 70 miles per hour. Back to Figure 73.

Figure 74. Bar graph. Color vision results for the three age groups by response. The graph is titled “Color Vision Results by Response.” The graph shows the participants’ color vision results by age group. The Y-axis shows the number of participants. The X-axis shows the 21 possible outcomes of the red-green color vision tests (there were 7 plates used, with 3 possibilities per plate: normal, red-green weak, and red-green blind). Outcomes for each age group (young, middle, and older) are represented by bars. All six of the older participants tested normal on every plate. The middle age group included all six participants testing normal on six out of seven plates, with one participant testing red-green weak on plate 6 (the remaining five testing normal on this plate). The young participants tested normal on the plates with the exception of the following: one tested red-green weak on plate 2, one tested red-green weak on plate 4, one tested red-green blind on plate 5, two tested red-green weak on plate 6, and one tested red-green blind on plate 7.
Back to Figure 74.

Figure 75. Bar graph. Color weak or color blind participants per age group. The graph is titled “Color Weak or Color Blind Participants.” The Y-axis shows the number of participants from 0 to 7. The X-axis shows three ranges of color vision: normal, red-green weak, and red-green blind. Young, middle-aged, and older participants are each represented by a different-styled bar. The graph shows that five young participants, all six middle-aged participants, and all six older participants are categorized as having normal vision. One young participant is categorized as having red-green weak vision. No participant is categorized as having red-green blind vision. Back to Figure 75.

Figure 76. Bar graph. Participant visual acuity per age group. The graph is titled “Participant Visual Acuity.” The Y-axis shows the number of participants from 0 to 6, and the X-axis shows visual acuity ranging from 20/6 to 20/40. Each age group of participants, young, middle-aged, and older, is represented by a different-styled bar. The distribution of participants for each level of visual acuity is as follows: 20/6 with one older; 20/7 with one middle-aged; 20/9 with one older; 20/13 with one young and one middle-aged; 20/15 with five young and one middle-aged; 20/20 with two middle-aged and three older; 20/25 with one middle-aged; and 20/40 with one older. Overall, the graph shows the most participants grouped at 20/15 and 20/20. Young participants are concentrated around 20/13 and 20/15 vision, while the other age groups are spread more evenly. Back to Figure 76.

Figure 77. Bar graph. Percentage of contrast for left eye (PCLE) and percentage of contrast for right eye (PCRE) at 1.5 cycles per degree (cpd) per age group. The graph is titled “Percentage of Contrast.” The Y-axis shows the number of participants from 0 to 7. The X-axis is split in half, representing the left eye and right eye. Each half shows the following range of percent of contrast at 1.5 cpd (cycles per degree): 0.83 (Good), 1.43, 2.86, 5.00, 8.33, 14.29, and 33.33 (Poor). Each age group of participants, young, middle-aged, and older, is represented by a different-styled bar. For the left eye, there were three young participants with 1.43 percentage of contrast, two with 2.86, and one with 5.00. There was one middle-aged participant with 0.83 (Good), three with 1.43, one with 2.86, and one with 5.00. All six older participants were at 2.86. For the right eye, all six young participants were at 1.43. There was one middle-aged participant with 0.83 (Good), two with 1.43, one with 2.86, and two with 5.00. All six older participants were at 2.86. Back to Figure 77.

Figure 78. Bar graph. Percentage of contrast at 3.0 cpd per age group. The graph is titled “Percentage of Contrast.” The Y-axis shows the number of participants from 0 to 5. The X-axis is split in half, representing the left eye and right eye. Each half shows the following range of percentage of contrast at 3.0 cpd (cycles per degree): 0.59 (Good), 1.13, 2.27, 4.17, 6.67, 11.11, and 25.00 (Poor). Each age group of participants, young, middle-aged, and older, is represented by a different-styled bar. For the left eye, there were three young participants with 0.59 percent contrast (Good), two with 1.13, and one with 2.27. There were four middle-aged participants with 0.59 (Good), one with 1.13, and one with 2.27. There was one older participant with 0.59 (Good), three with 1.13, and two with 2.27. For the right eye, there were two young participants with 0.59 (Good) and four with 1.13. There were three middle-aged participants with 0.59 (Good), one with 1.13, and two with 2.27. There were two older participants with 1.13 and four with 2.27. Back to Figure 78.

Figure 79. Bar graph. Percentage of contrast at 6.0 cpd per age group. The graph is titled “Percentage of Contrast.” The Y-axis shows the number of participants from 0 to 5. The X-axis is split in half, representing the left eye and right eye. Each half shows the following range of percentage of contrast at 6.0 cpd (cycles per degree): 0.54 (Good), 0.8, 1.43, 2.22, 4.76, 9.09, and 20.00 (Poor). Each age group of participants, young, middle-aged, and older, is represented by a different-styled bar. For the left eye, there were three young participants with 0.54 percent of contrast (Good), two with 0.8, and one with 2.22. There were four middle-aged participants with 0.54 (Good) and two with 2.22. There were two older participants with 0.8, one with 1.43, and three with 2.22. For the right eye, there were two young participants with 0.54 (Good) and four with 0.8. There were two middle-aged participants with 0.54 (Good), one with 0.8, one with 1.43, and two with 2.22. There were three older participants with 0.8 and three with 2.22. Back to Figure 79.

Figure 80. Bar graph. Percentage of contrast at 12.0 cpd per age group. The graph is titled “Percentage of Contrast.” The Y-axis shows the number of participants from 0 to 6. The X-axis is split in half, representing the left eye and right eye. Each half shows the following range of percentage of contrast at 12.0 cpd (cycles per degree): 0.80 (Good), 1.14, 1.82, 3.13, 6.67, 12.5, and 20.00 (Poor). Each age group of participants, young, middle-aged, and older, is represented by a different-styled bar. For the left eye, there were five young participants with 1.14 percent of contrast and one with 1.82. There was one middle-aged participant with 0.80 (Good), two with 1.14, one with 1.82, and two with 6.67. There was one older participant with 1.14, one with 1.82, three with 6.67, and one with 12.5. For the right eye, there were five young participants with 1.14 and one with 1.82. There was one middle-aged participant with 0.80 (Good), two with 1.14, one with 3.13, and two with 6.67. There were two older participants with 1.14, one with 1.82, two with 6.67, and one with 12.5. Back to Figure 80.

Figure 81. Bar graph. Percentage of contrast at 18.0 cpd per age group. The graph is titled “Percentage of Contrast.” The Y-axis shows the number of participants from 0 to 5. The X-axis is split in half, representing the left eye and right eye. Each half shows the following range of percentage of contrast at 18.0 cpd (cycles per degree): 1.54 (Good), 2.50, 3.85, 6.67, 10.00, 14.29, and 25.00 (Poor). Each age group of participants, young, middle-aged, and older, is represented by a different-styled bar. For the left eye, there were two young participants with 2.50 percent of contrast and four with 3.85. There was one middle-aged participant with 1.54 (Good), two with 2.50, one with 6.67, one with 10.00, and one with 25.00 (Poor). There were two older participants with 3.85, two with 10.00, and two with 25.00 (Poor). For the right eye, there were two young participants with 2.50 and four with 3.85. There were two middle-aged participants with 2.50, two with 6.67, one with 10.00, and one with 25.00 (Poor). There were two older participants with 2.50, two with 10.00, and two with 14.29. Back to Figure 81.

Figure 82. Bar graph. Instrument panel brightness setting by age group (headlamp VESs only). The graph is titled “IP Brightness Setting for Age Groups—Headlamp VESs only.” The Y-axis shows instrument panel brightness ranging from 0 to 1 by tenths. The X-axis indicates age category (Young, Middle, Older), and there is one bar for each age category. Standard error bars are also provided for each graph bar. Young participants have a mean instrument panel brightness value of just over 0.5, middle-aged participants have a value of just over 0.4, and older participants have a value of just over 0.3. The standard error bar for the older group is slightly smaller than the bars for the other age groups. A note on the graph indicates that the mean instrument panel brightness settings are not significantly different by age group (p value equals 0.57). Back to Figure 82.

Figure 83. Bar graph. VES by Age interaction for display brightness setting. The graph is titled “Display Brightness Setting – Interaction of VES by Age.” The Y-axis shows the display brightness setting from 0 to 1 by tenths. The X-axis shows three types of VESs: FIR, NIR 1, and NIR 2. Each type of VES has three bars representing young participants, middle-aged participants, and older participants. Each bar also has a standard error bar at its top. The approximate display brightness settings for FIR are as follows for each age group of participants: young, 0.65; middle-aged, 0.80; and older, 0.55. The approximate display brightness settings for NIR 1 are as follows: young, 0.45; middle-aged, 0.38; and older, 0.20. The approximate display brightness settings for NIR 2 are as follows: young, 0.60; middle-aged, 0.80; and older, 0.85. Standard error bars are smallest for the younger and middle age groups using the NIR 1 system, and are largest for the younger group using the FIR system. A note on the graph indicates that the mean display brightness settings are not significantly different for the VES by Age interaction (p value equals 0.0924). Back to Figure 83.

Figure 84. Scatter plot. Participant eye position for all vehicles. The graph is titled “Eye Position—All Vehicles.” The Y-axis shows eye height above pavement in millimeters. The X-axis shows forward measure in millimeters, decreasing left-to-right. Each vehicle, FIR, NIR 1, NIR 2, HLB, HID 1, and HID 2, has its own style of data point. The scatter plot shows the bulk of the data ranging from around 300 millimeters to 100 millimeters for the forward measure and 1,400 millimeters to 1,575 millimeters for the eye height above pavement. NIR 1 appears to generally have the highest eye height, ranging from approximately 1,500 to 1,640 millimeters, and a widespread forward measure ranging from around 300 to 90 millimeters. FIR and NIR 2 are the next highest and about as far forward as NIR 1. FIR and NIR 2 have similar measurements; eye height generally ranges from around 1,480 to 1,580 millimeters, and forward measure ranges from around 290 to 115 millimeters (with the exception of a 311-millimeter (FIR) and a 356-millimeter (NIR 2) measurement). HLB, HID 1, and HID 2 are the lowest to the ground, and they all have similar measurements. Eye height generally ranges from 1,380 millimeters to 1,530 millimeters. Forward measure is also equally distributed between HLB, HID 1, and HID 2, showing measures generally between about 310 and 110 millimeters. Back to Figure 84.

Figure 85. Diagram. Eye position measurement locations for all experimental vehicles (forward measure taken from leading edge of B-pillar weather seal). The picture shows a stylized drawing of the ground and a section of an automobile above it, showing from the front of the driver’s door to its rear. A driver is in the vehicle. A double-headed arrow extends vertically between the ground and the driver’s eye height, showing the eye height above the pavement. Another double-headed arrow extends horizontally between the driver’s eye and the leading edge of the B-pillar weather seal (the area where the window and the rear of the door frame join), showing the forward measure. Back to Figure 85.

Figure 86. Scatter plot. Participant eye position for FIR. The graph is titled “Eye Position—FIR.” The Y-axis shows eye height above pavement in millimeters. The X-axis shows forward measure in millimeters, decreasing left-to-right. Eye height measures for FIR range from around 1,480 millimeters to 1,580 millimeters. Forward measures range from around 270 millimeters to 115 millimeters, with the exception of one measurement at around 310 millimeters. Back to Figure 86.

Figure 87. Scatter plot. Participant eye position for NIR 1. The graph is titled “Eye Position—NIR 1.” The Y-axis shows eye height above pavement in millimeters. The X-axis shows forward measure in millimeters, decreasing left-to-right. Eye height measures for NIR 1 range from around 1,500 millimeters to 1,635 millimeters. Forward measures range from around 255 millimeters to 90 millimeters, with the exception of one measurement at about 300 millimeters. Back to Figure 87.

Figure 88. Scatter plot. Participant eye position for NIR 2. The graph is titled “Eye Position—NIR 2.” The Y-axis shows eye height above pavement in millimeters. The X-axis shows forward measure in millimeters, decreasing left-to-right. Eye height measures for NIR 2 range from around 1,520 millimeters to 1,585 millimeters, with the exception of one measurement at about 1,485 millimeters. Forward measures range from around 285 millimeters to 115 millimeters, with the exception of one measurement at about 360 millimeters. Back to Figure 88.

Figure 89. Scatter plot. Participant eye position for HLB. The graph is titled “Eye Position—HLB.” The Y-axis shows eye height above pavement in millimeters. The X-axis shows forward measure in millimeters, decreasing left-to-right. Eye height measures for HLB range from around 1,405 millimeters to 1,490 millimeters. Forward measures range from around 290 millimeters to 155 millimeters, with the exception of one measurement at about 110 millimeters. Back to Figure 89.

Figure 90. Scatter plot. Participant eye position for HID 1. The graph is titled “Eye Position—HID 1.” The Y-axis shows eye height above pavement in millimeters. The X-axis shows forward measure in millimeters, decreasing left-to-right. Eye height measures for HID 1 range from around 1,385 millimeters to 1,500 millimeters. Forward measures range from around 285 millimeters to 165 millimeters, with the exception of one measurement at about 110 millimeters. Back to Figure 90.

Figure 91. Scatter plot. Participant eye position for HID 2. The graph is titled “Eye Position—HID 2.” The Y-axis shows eye height above pavement in millimeters. The X-axis shows forward measure in millimeters, decreasing left-to-right. Eye height measures for HID 2 range from around 1,380 millimeters to 1,535 millimeters. Forward measures range from around 255 millimeters to 155 millimeters, with the exception of one measurement at around 310 millimeters and one at 110 millimeters. Back to Figure 91.

Appendix C: Diagram. Contrast sensitivity test. The diagram shows the form the experimenters used to document the results for each participant’s contrast sensitivity exam. The diagram shows a graph with contrast sensitivity from 3 to 300 on the left Y-axis, contrast threshold from .3 to .003 on the right Y-axis, and spatial frequency (cycles per degree) from .5 to 6 on the X-axis. There is a column of numbered circles above each cycle per degree, indicating participant response. There are two diagrams, one for recording the results of the right eye and one for the results of the left eye. Back to Diagram.

Appendix D: Predrive Questionnaire Rating Scales, Question 3. Question 3 and its answer choices (presented on a four-point scale moving left to right) are: “Would you say you drive at night with (Please circle only one): ‘no difficulty,’ ‘little difficulty,’ ‘moderate difficulty,’ or ‘extreme difficulty.’” Back to Question 3.

Appendix D: Predrive Questionnaire Rating Scales, Question 4. Question 4 and its answer choices (presented on a four-point scale moving left to right) are: “While driving at night, oncoming headlights and streetlights cause you...(Please circle only one): ‘no difficulty,’ ‘little difficulty,’ ‘moderate difficulty,’ or ‘extreme difficulty.’” Back to Question 4.

Appendix D: Predrive Questionnaire Rating Scales, Question 5. Question 5 and its answer choices (presented on a five-point scale moving left to right) are: “In general, how do you feel about driving at night in good weather? (Please circle only one): ‘very comfortable,’ ‘somewhat comfortable,’ ‘neither comfortable nor uncomfortable,’ ‘somewhat uncomfortable,’ or ‘very comfortable.’” Back to Question 5.

Appendix D: Predrive Questionnaire Rating Scales, Question 6. Question 6 and its answer choices (presented on a five-point scale moving left to right) are: “In general, how do you feel about driving at night in typical bad weather conditions (light rain, snow, fog)? (Please circle only one): ‘very comfortable,‘ ‘somewhat comfortable,’ ‘neither comfortable nor uncomfortable,’ ‘somewhat uncomfortable,’ or ‘very comfortable.’”
Back to Question 6.

 

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