U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590

Skip to content

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

PDF Version (1.03 MB)

PDF files can be viewed with the Acrobat® Reader®


Study 3 in Phase II of the Enhanced Night Visibility (ENV) project was the second in a series of three studies tested at the Smart Road testing facility in Virginia that focused on drivers' visual performance during adverse weather conditions such as rain, snow, and fog. The experimental tasks for this study consisted of driving at nighttime in snowfall conditions of snowfall using 4 different vision enhancement system (VES) configurations taken from the original set of 12 used for Phase II–Studies 1 and 2, ENV Volumes III and IV. Drivers' visual performances were evaluated in terms of detection and recognition distances for different objects while using the different VESs. Subjective performance ratings were garnered from questionnaires administered to participants following the use of each VES.

The driving portion of the study took place at the Smart Road testing facility in Virginia. The road was closed to all traffic except experimental vehicles, and no more than two vehicles were on the road at any time. Participants underwent a training session and participated in the onroad study in one night. The next chapter describes methods used in this study.


Table of Contents       Next
Federal Highway Administration | 1200 New Jersey Avenue, SE | Washington, DC 20590 | 202-366-4000
Turner-Fairbank Highway Research Center | 6300 Georgetown Pike | McLean, VA | 22101