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Federal Highway Administration Research and Technology
Coordinating, Developing, and Delivering Highway Transportation Innovations

This report is an archived publication and may contain dated technical, contact, and link information
Publication Number: FHWA-HRT-04-136
Date: December 2005

Enhanced Night Visibility, Volume V: Phase II—Study 3: Visual Performance During Nighttime Driving in Snow

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Pre-Experiment Duties

  1. Attend the nightly meeting. Get the following forms from the in-vehicle experimenter:
    • VES order and diagram hand out.
    • Vehicle prep sheets.
    • Participant eye measurement sheet.
    • Lead valet vehicle checklist.
    • Ambient light reading (lux) form.
  2. Prep the vehicles according to the vehicle prep sheet.
  3. Make sure that you have the following equipment:
    • Flashlight.
    • Safety glasses.
    • Radios.
    • Eye measurement equipment.
    • Vest.
    • Rags to wipe headlamps if needed.
    • Deicer.
    • 10 cones.
    • Ice scraper.
  4. Park the SUVs in front of the building.
  5. With the assistance of the onroad experimenters, perform the road prep according the road prep sheet.
  6. Drop off all onroad experimenters at their stations:
    • Valet #2 (in pickup) to stations 2 and 4.
    • Lead valet (in large SUV) to stations 1 and 5.
  7. Valet # 2 - Park the pickup in the gravel below T3 perpendicular to the road (facing away from the mountain.
  8. Valet # 1 - Park the Large SUV at T2.
  9. Make sure that your radio is on channel 8.
  10. Wait for drivers to arrive at T2.

Duties During the Experiment


  1. Check that headlamps are clean on the two vehicles. If not, clean and apply more deicer.
  2. Remove ice from windshield on the two vehicles. If there is significant buildup of ice on the wipers, the defrost heater setting should be used, but it must be turned to heat while the vehicle is sitting.
  3. Whenever SUV 2 arrives at the turnaround, the generator must be connected to the vehicle. This is done by moving the generator cart close to the rear of the SUV and connecting the red plug of the generator to that of the SUV. The AC power switch on the generator is then turned on. A road cone must be placed at the tongue of the generator cart to ensure that participants do not trip if they are moving between vehicles.
  4. Take eye height measurements for each participant in each vehicle. To do this, first explain to the participant that you are going to make a mark on the window as to where their eye level is located. Instruct them to adjust their seat to where they think they will be comfortable. Once they are situated, tell them to look ahead, relax, and stay as still as possible. Close the door and take the measurements.
    • Use the level (located in valet box) to assess participant's eye position. Once you have found their eye position mark a "+" on the glass (using a dry-erase marker).
    • Using the "+" as a reference point, take measurements (horizontal and vertical).
    • Take vertical measurement with metal end of tape measure down where the glass intersects with the black plastic.
    • Take horizontal measurement with metal end of tape measure to the right where glass intersects with black plastic.
  5. When SUV 2 is ready to return to the road for the next lap, the generator must be disconnected from the vehicle. This is performed by turning the AC power switch on the generator to off and unplugging the power connector. The connector should be returned to the holding location on the side of the cart. The cart must then be moved back to the location at the side of the turn around.
  6. The first parking space on each side is termed a "vehicle drop off" and needs to be available at the end of every lap. The valets will move any vehicle that is left in those locations to the parking spots outside the turn around. The generator and cart must be moved as well.
  7. Whenever possible, the first driver that returns to the middle turnaround should have their next vehicle waiting for them at the foremost parking spot. Valets will need to look at the VES order sheet to determine which vehicle will be used next and which parking spots should be used to ensure that the driver's wait-time is minimized.
  8. The status of temperature and battery must be recorded on the lead valet checklist for all vehicles (This must be done with the generator unhooked for SUV 2). This is read from the instrument panel of the vehicle. If the participant has the instrument panel lights off, after the in-vehicle experimenter has completed their questions radio to them and ask that the participant turn on the lighting for the readings.
    • If the temperature is too high, radio to the in-vehicle experimenter that the defrost system of the vehicle must be turned off and the setting should be to the floor setting only. The temperature should start to drop. At no point should the heating system be turned off. This will cause the vehicle to overheat.
    • If the voltage is too low (likely in SUV 2 only), radio to the in-vehicle experimenter that the voltage is low and that more time is needed with the generator. It is likely that an outside of the vehicle discussion will be required. Do not let the participant know the nature of the discussion.
  9. Before driver goes down the road, ensure the headlights are on and working. use safety glasses.
    • White SUV1: If Low UV–A is required, make sure they are working. Otherwise, make sure the two HLBs are on.
    • White SUV2: If High UV–A is required, all five should be on. Report if one is not working or extremely dull. The HLB lights should be working at all times.
    • Large SUV: The two HID headlamps on the front of the vehicle should be on.
  10. Valet 2 wait outside turnaround 3 until the vehicle has come to a complete stop.
  11. Check VES configuration for the experimenter.
  12. Check that headlamps are clean on the two vehicles. If not, clean and apply more de icer.
  13. Remove ice from windshield on the two vehicles.

Between Subject Procedures

  1. Valet 2 should retrieve the pickup and retrieve stations 2 and 4.
  2. Valet 2 should then drive to turnaround 2 and drop someone at SUV 1, who will then go back and pick up stations 1 and 5.
  3. The lead valet should take SUV 2 and begin taking the ambient light measurements. Do not take them if the other vehicle is on the road.
  4. The onroad experimenters will return to the building for a break.
  5. Change the following radio batteries before returning to the road:
    • Two in-vehicle radios.
    • Two radios from stations 1 and 5.
    • Two radios from stations 2 and 4.
  6. The two SUVs must be returned to the front of the building in preparation for the next participants.
  7. The onroad experimenters will be returned to the road in the pickup and large SUV as at the beginning of the experiment.
  8. Repeat this protocol when running a double or triple shift.

Shut Down Procedures

  1. Pick up all onroad experimenters and all onroad materials.
  2. Sign in all the radios.
  3. Make sure that all radios and batteries are accounted for.
  4. Make sure the power is off when you put the radios into the charger.
  5. Submit paperwork to in-vehicle experimenter.

General Notes for the Valet

Outside of the vehicle discussion should be had with the in-vehicle experimenter whenever problems arise or questions need to be answered. At no point should a discussion about the experiment or the road conditions be held with hearing distance of the participant.
While a participant is outside of the vehicle or the vehicle doors are open, the valet must turn the volume of their radio low so that the participant does not know the nature of the experiment or conditions on the road.


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