An evaluation of stop signs used with flashing traffic signals. Final report.

Turner-Fairbank Highway Research Center, McLean, Va.

Guidelines for flashing traffic control devices. Final report.

Federal Highway Administration, Office of Research and Development, Washington, D.C.

Evaluation of flashing traffic signal operation. Final report.

Texas Department of Transportation, Austin

A study of clearance intervals, flashing operation, and left-turn phasing at traffic signals. Volume 1: sumary report. Final report.

Federal Highway Administration, Office of Research and Development, Washington, D.C.

A study of clearance intervals, flashing operation, and left-turn phasing at traffic signals. Volume 2: clearance intervals. Final report.

Federal Highway Administration, Office of Research and Development, Washington, D.C.

A study of clearance intervals, flashing operation, and left-turn phasing at traffic signals. Volume 3: flashing operation. Final report.

Federal Highway Administration, Office of Research and Development, Washington, D.C.

Sunglasses, traffic signals, and color vision deficiencies

Purpose: To determine (a) the effect of different sunglass tint colorations on traffic signal detection and recognition for color normal and color deficient observers, and (b) the adequacy of coloration requirements in current sunglass standards. Methods: Twenty color-normals and 49 color-deficient males performed a tracking task while wearing sunglasses of different colorations (clear, gray, green, yellow-green, yellow-brown, red-brown). At random intervals, simulated traffic light signals were presented against a white background at 5° to the right or left and observers were instructed to identify signal color (red/yellow/green) by pressing a response button as quickly as possible; response times and response errors were recorded. Results: Signal color and sunglass tint had significant effects on response times and error rates (p < 0.05), with significant between-color group differences and interaction effects. Response times for color deficient people were considerably slower than color normals for both red and yellow signals for all sunglass tints, but for green signals they were only noticeably slower with the green and yellow-green lenses. For most of the color deficient groups, there were recognition errors for yellow signals combined with the yellow-green and green tints. In addition, deuteranopes had problems for red signals combined with red-brown and yellow-brown tints, and protanopes had problems for green signals combined with the green tint and for red signals combined with the red-brown tint. Conclusions: Many sunglass tints currently permitted for drivers and riders cause a measurable decrement in the ability of color deficient observers to detect and recognize traffic signals. In general, combinations of signals and sunglasses of similar colors are of particular concern. This is prima facie evidence of a risk in the use of these tints for driving and cautions against the relaxation of coloration limits in sunglasses beyond those represented in the study.

Using light emitting diodes in traffic signals -- final report.

Federal Highway Administration, Washington, D.C.

User guide for removal of not needed traffic signals.

Federal Highway Administration, Washington, D.C.

Visibility and comprehension of pedestrian traffic signals /

"May 1997."

Efficacy of red and yellow turn arrows in traffic signals. Final report.

Federal Highway Administration, Washington, D.C.

Advance traffic control warning systems for maintenance. Final report.

Federal Highway Administration, Baton Rouge, Fla.

Criteria for removing traffic signals, technical report /

Mode of access: Internet.

Guidelines for the application of arrow boards in work zones. Final report.

Federal Highway Administration, Office of Research, Washington, D.C.

Evaluation of dynamic sign systems for narrow bridges. Final report.

Federal Highway Administration, Office of Research, Washington, D.C.