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Publication Number: FHWA-HRT-04-149
Date: December 2005

Alternate Text for Enhanced Night Visibility Volume XVIII Overview of III

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Figure 1. 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 shown. 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 raised retroreflective pavement markings. 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 1.

Figure 2. Diagram. Infrared thermal imaging system 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 shown. 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 far infrared visibility enhancement system. The right side of the grid presents labels at the approximate stopping distances necessary for various speeds. The left-turn left pedestrian, the arrow, 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 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-turn pedestrian in black and the 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 2.

Figure 3. Diagram. Near infrared 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 near infrared 1 visibility enhancement system. 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 3.

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