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Publication Number: FHWA-HRT-04-135
Date: December 2005

Enhanced Night Visibility, Volume IV: Phase II—Study 2: Visual Performance During Nighttime Driving in Rain

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APPENDIX F—IN-VEHICLE EXPERIMENTAL PROTOCOL


IN-VEHICLE PROTOCOL FOR NIGHT 1 AND 2

Night 1
  1. Greet participant.

  2. Record the time of their arrival on the debriefing sheet.

  3. Orient them to the vehicle.
    • Take participant to the vehicle parked outside the front door.
    • Check which vehicle they will do their first VES in and have them drive that vehicle if it is available.
    • Show them how to adjust their seat, interior display lights, the windshield wipers, and the steering wheel. Say: You will notice that your side and rearview mirrors have been covered. This is to reduce the glare that you might get from other vehicles.
    • Explain to them how to turn on and off the parking lights.
    • Make sure they are wearing their seatbelt.

  4. Turn on the baseline VES for the drive to the road and practice lap.
    • SUVs use HLB or HID—NO UV.
    • Pickup use HOH or HHB.
    • Sedan use regular lights—NO IR.

  5. Make sure that you are wearing your seatbelt.

  6. Instruct the driver to drive to the Smart Road.

  7. Radio the control room to ask for the gate to be opened, and tell them the number of cars entering the road.

  8. Proceed to the parking spots at the bottom turnaround. Keep a moderate distance between vehicles.
    • First vehicle at the bottom of the hill:
    • Pull all the way to the first parking space.
    • Put the vehicle in park and have the participant take their foot off the brake.
    • Ask driver to turn off wipers if it is not raining at the turnaround.
    • Ask the driver to turn off the parking lights so the brake lights do not create a lighter background when reflected on the rain.

     

    • Second vehicle at the bottom of the hill:
    • Pull into the second parking space.
    • Put the vehicle in park and have the participant take their foot off the brake.
    • Ask driver to turn off wipers if it is not raining at the turnaround.
    • On the second lap of each VES, the second car down should pull up to the second lap parking space instead of the usual space.

  9. Review instructions with participant (This may be done while driving down the road or while parked at the bottom turnaround).
    • Show them the button.
    • Read the following instructions:

    I will need you to hold this in your hand during the study. When you press this you will hear a beep. Once the study begins I need you to press the button as soon as you detect an object.

    Detection is when you can just tell that something is on the road in front of you. You cannot tell what the object is but you know something is there.

    When you can accurately recognize an object, I would like you to press the push button again and recognize the object verbally at the same time.

    Recognition is when you not only know something is there but you also know what it is.

    You will need to be specific when you recognize. If you see an object, you will need to tell me what the object is.

    For example,

    “I see a person”

    “I see a cyclist”

    “I see a kid’s bike”

    “I see a tire tread”

    If you perform an unsuccessful recognition, you can press the push button again and then verbally recognize the object.

    • Hand them the button.

  10. Radio the onroad experimenters that you are ready to begin.

  11. Orient participant to Smart Road.

    First we will drive up the road to get you used to the road, the rain, and the vehicle. You will need to drive up the center of the road. Go ahead and drive up the road at 25 miles per hour. When we enter the section of road where the rain towers are turned on, you need to be going 10 miles per hour.

    • Allow the participant to drive up the road.
    • Remind the driver to turn on the windshield wipers before they get to the rain.
    • Remind them to drive in the center of the road.
    • The second vehicle can begin once the first vehicle is out of sight.
    • Remind them of the speed limit if necessary.

    First vehicle at the top of the hill:
    • Pull all the way to the cone at front parking space in the left lane.
    • Put the vehicle in park and have the participant take their foot off the brake.
    • Ask driver to turn off the wipers if it is not raining at the turnaround.
    • Reverse into the entrance of the gravel lot after the second car is out of sight.
    • Wait for station 2 to tell you it is alright to proceed down the hill.

    Second vehicle at the top of the hill:
    • Pull into the second parking space at the cone in the right lane.
    • Ask driver to turn off the wipers if it is not raining at the turnaround.
    • Reverse into the entrance of the gravel lot and proceed down the hill.


  12. Let drivers do a practice run down the Smart Road.

    We will now practice while you drive down the hill to help you get used to driving the vehicle on the Smart Road and using the push buttons. I would like you to drive down the center of the road at 10 miles per hour.
    • Remind the driver to turn on the windshield wipers.
    • Remind the participant how to recognize the different objects.

    On the way down we will practice how to detect and recognize objects. You will see two different objects. Please remember to say:

    “I see a person”

    “I see a tire tread”

    If you perform an unsuccessful recognition, you can press the push button again and then verbally recognize the object.

  13. Set up the computer at the top of the hill parking area if you haven’t already done so.
    • Enter participant information (ID, Age, Gender).
    • Enter current setup information (VES, object order, night 1, 2, or 3).
    • Start the computer program.
    • Check that the computer program is reading the correct calibration value.
    • Start the data collection when you are parallel to luminaire 6 (the first light tower after the gravel lot).
    • Note that there is space at the bottom of the screen for error messages. Check to make sure that you are not receiving any error messages.

    It is VERY important that you do not talk to the drivers when you are collecting data. This means no talking during the entire section of the road where the rain towers are on. EMERGENCIES EXCLUDED!

  14. Monitor the computer while going down the hill.
    • Make sure that the value in the “Current Distance” field is increasing. This ensures the DMI is working.
    • When driver presses button the first time, the computer should beep and record the “Detection Dist.”
    • After they press button the second time, the computer should beep and record the “Recognize Dist.”
    • Press the computer space bar again when your body is in line with the object. After space bar is pressed, the arrow will scroll down to the next object.
    • Press the ESC key if the driver presses the button on accident or states that they made a false detection.
    • Press the ESC key if the driver makes an unsuccessful recognition.
    • During the practice run, you may need to assist the participant. For example, if they do not indicate the detection or recognition points and the object is close to 50 feet, you need to say, “We are very close to the first object please press the push button as soon as you can detect it and then once again when you can recognize it.

  15. Proceed to the parking spots at the bottom turnaround.
    First vehicle at the bottom of the hill:
    • Pull all the way to the first parking space.
    • Put the vehicle in park and have the participant take their foot off the brake.
    • Ask driver to turn off the wipers if it is not raining at the turnaround.
    • Ask the driver to turn off the parking lights so the brake lights do not create a lighter background when reflected on the rain.

    Second vehicle at the bottom of the hill:
    • Pull into the parking space next to the first car.
    • Put the vehicle in park and have the participant take their foot off the brake.
    • Ask driver to turn off the wipers if it is not raining at the turnaround.

  16. Ask driver the nine questions about the VES.
    • You may begin to ask the questions when the driver is past the rain, if you are comfortable doing so. If not, wait until they are parked.
    • Remind subjects of the 1-7 scale, where 1 is Strongly Agree and 7 is Strongly Disagree.
    • Type in their response.

  17. Document the windshield wiper speed for each run.
    • This is a subjective rating of “low,” “med,” or “high.” It is recorded on the back of the data error sheet.
    • If driver changes the wiper speed significantly in the middle of a run, the experimenter will document the wiper speed used for each of the two stations.

  18. Document any unexpected events that occurred during the previous run on the data error sheet.

  19. Prepare for the first VES.
    • Make sure you are in the correct vehicle, using your VES order sheet.
    • Select the proper VES and order on the computer.
    • Let the valet check the headlamps-make sure valet uses the diagram to ensure the proper VES is being used.
    • Wait for the OK from the onroad experimenters.
    • Continue up the road.

  20. Start data collection for first VES when you are parallel with the guardrail at the bottom of the hill.
    • Monitor the safety of the cyclists on the road.
    • Use the computer program to determine when you are approaching a cyclist.
    • Say “station X, clear” as soon as the participant identifies the cyclist.
    • If driver does not see cyclist, use the computer DMI readout to determine when the vehicle is within 50 feet of cyclist. Tell the cyclist to clear at that time.

  21. Continue the same procedure for the rest of the VES.

  22. Bring participants back to the building.
    • Have both participants and both experimenters get in the nonexperimental vehicle. One experimenter will drive all four back to the building.


  23. Remind participants of their next scheduled drive.
Night 2
Protocol is very similar to night 1.
  • Follow steps 1 through 9.
  • Skip the orientation run.
  • Skip the practice run.
  • Set up the computer at the bottom of the road.
  • Wait for onroad to radio that they are ready.
  • Collect data using the protocol from night 1.
  • Take drivers back to the building.
  • Complete the hours/amount paid section of debriefing form.
  • Ask drivers to fill out the payment receipt log.
  • Pay the drivers, and thank them for their participation.

 

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