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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-04-145
Date: December 2005

Enhanced Night Visibility Series, Volume XIV: Phase III—Study 2: Comparison of Near Infrared, Far Infrared, and Halogen Headlamps on Object Detection in Nighttime Rain

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  1. Prior to the participants’ arrival, make sure that all the needed forms are available.
  2. Set up the conference room.
    • Close all the shades.
    • Turn on all overhead lights.
    • Turn off halogen lamps.
    • Position work light for vision contrast by placing it within the tape on the floor. Get color vision test, BAT, eye occluder, alcohol, and cotton balls from prep room.
  3. Greet participant.
  4. Record the time that the participant arrived on the debriefing form.
  5. Show driver’s license.

    Before we begin, it is required for me to verify that you have a driver’s license. Would you please show me your license?
    Must be a valid Class A driver’s license to proceed with the study. Out of state is fine.

    Experimenter reads all text in italics aloud to each participant:

    Now I have some paperwork for you to fill out. This first form tells you about the study, what your job is, and any safety risks involved in the study. Please read through the document. If you have any questions, please feel free to ask. If not, please sign and date the paper on the last page.

    • Give the participant the form
    • Answer questions
    • Have participant sign and date both forms
    • Give the participant a copy of the informed consent

  6. Tax forms.
    To complete the W-9, the participant must fill out the following in the box:

    • Name
    • Address
    • Tax ID number (social security number)
    • Sign and date at the bottom
    The other side of the form is a University Voucher stating they are not being “permanently” employed by our project. Have them print their name on the top of the form.

  7. Vision tests.

    Follow me and I will go through the vision tests with you.
    The results for all three parts must be recorded on the Vision Test Form.

    The first test is the Snellen eye chart test.
    • Take the participant over to the eye chart test area.
    • Line up their toes to the line on the floor (20 feet).
    • Participants can leave on their glasses if they wear them for driving.
      Procedure: Look at the wall and read aloud the smallest line you can comfortably read.
    • If the participant gets every letter on the first line they try correct have them try the next smaller line. Continue until they miss a letter. At that time, record the one that they were able to read in full (line above).
    • If they get the first line they attempt incorrect, have them read the previous line. Repeat as needed until they get one line completely correct. Record this acuity.

      The next vision test is the Contrast Sensitivity test. Take the participant over to the eye chart test area.

    • Line up their toes to the line on the floor (10 feet).
    • Participants can leave on their glasses if they wear them for driving.
      Procedure: We are going to test how well you see bars at different levels of contrast. Your ability to see these bars relates to how well you see everyday objects. It is VERY IMPORTANT you do not squint or lean forward while you are taking the test.
    • Point out the sample patches at the bottom of the chart with the three possible responses (left, right, or straight).
    • Cover one eye with an occluder. (DO NOT let the participant use his/her hand to cover the eye since pressure on the eye may cause erroneous contrast sensitivity test results).
    • Instruct the participant to begin with Row A and look across from left to right. Ask the participant to identify the last patch in which lines can be seen and tell you which direction they tilt. If the response is incorrect, have the participant describe the preceding patch.
    • Use the table in the ENV binder to determine if subjects’ answers are correct.
    • Each vertical column of numbers on the second part of the Vision Test form corresponds to a horizontal row on the chart. Record the last patch the participant correctly identifies in each row by marking the corresponding dot on the form.
    • To form the participant’s contrast sensitivity curve, connect the points marked.
    • Cover the other eye and repeat all the steps above.

      The next vision test is the Test for Color Blindness.

    • Take the participant back to his/her desk.
    • Place the book containing the plates on the testing apparatus

      Please hold the red end of this handle to your nose and read the number on the following plates.

    • Record the participants answers on the Vision Tests Form

      The last test is the Brightness Acuity Test

    • Go to the 20 ft line for the Snellen Test.
    • Give the participant the BAT to hold up to one eye.
    • Instruct the participant to cover their other eye.
    • Repeat Snellen Test in each eye for all levels of the BAT (off/ low/ medium/ high).

  8. Measure participant height
  9. Administer PreDrive Questionnaire
  10. Orient driver to the study

    Tonight you will drive one vehicle for approximately 2.5 to 3 hours. We will drive under two different levels of interior lighting in the vehicle. You will be driving past several different sets of oncoming headlamps and looking for pedestrians along the roadway.

    I will be in the vehicle with you at all times. I will provide directions where to go, record data, and I can answer any questions you have. As you drive, there will be pedestrians I would like you to identify.

    When you can detect the pedestrian as a person and you can tell which side of the road they are on, say “Person Left” or “Person Right”.

    If there are no pedestrians you do not need to say anything.

    (Show picture of pedestrian)

    There will also be other cars on and around the road. You never need to call out a vehicle as an object.

    We’ll first do a practice lap before we begin where I’ll tell you what to look for and you can get used to the vehicle , then we’ll do the experimental portion.

    The maximum speed limit during the drive will be 20mph. To assist you with keeping the vehicle at the low speed of 20 mph we will use second gear. The vehicle should also be on low beams at all times.

    Do you have any questions at this time?
    (Answer questions if needed).

  11. Review the Discomfort Rating Scale

    During a portion of tonight’s study, after you are finished driving past a set of oncoming headlamps, I will ask you to rate the discomfort you experienced from the headlamps.
    (Review Scale)

    Once you give an answer, you will not be able to change it.

  12. Before leaving the building ask if they want to use the restroom.


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