NCHRP Research Report 1085 presents proposed guidelines for vehicle and equipment color, marking, and lighting practices. Static and dynamic tests were conducted to measure the effects of alternative vehicle marking and warning light treatments on driver perception of workers on foot and of moving work vehicles fitted with the treatments. Testing was also conducted to measure the effects of the alternative treatments on driver lane choice and speed. These guidelines will particularly benefit state Department of Transportation (DOT) operations personnel by more effectively identifying and communicating their presence to nearby motorists.

The timely recognition of vehicle activity represents a critical safety consideration within the roadway network. Roadway operations equipment used by state DOTs and transportation agencies for activities such as construction, maintenance, and incident response generally deploys on all types of roadways, during daytime and nighttime hours, and in all weather conditions. To improve motorist and worker safety, equipment must be readily seen and recognized; hence, appropriate colors, retroreflective markings, and warning lights must be provided on the equipment to alert motorists of potentially hazardous situations. However, different colored warning lights, vehicle colors, and retroreflective markings have been used for the same vehicle types, creating concern that such variety does not adequately consider the associated effects on the awareness and responsiveness of motorists.

In NCHRP Project 05-24, “Guidelines for Vehicle and Equipment Color, Marking, and Lighting,” the Texas A&M Transportation Institute was asked to develop (1) recommendations for the selection and application of color, retroreflective markings, and lighting to vehicles and equipment; and (2) proposed language for consideration by the American Association of State Highway and Transportation Officials (AASHTO) to incorporate into the next update of the AASHTO Guidelines for the Selection and application of Vehicle Markings and Warning Lights on Roadway Operations Vehicles and Equipment. The research determined that vehicle markings, especially unique ones, assist in nighttime detection of workers on foot; the use of arrayed warning lights, color, and flash speed may increase perception of hazard urgency but also increase distraction and visual discomfort; and irregular flash patterns reduce motorist detection of workers and perception of hazard urgency.

NCHRP Research Report 1085 describes the entire research effort and includes four appendices:

• Prioritization of Vehicle Marking and Warning Light Attributes
• Daytime Static Closed-Course Study Experimental Design and Statistical Analyses
• Nighttime Static Closed-Course Study Experimental Design and Statistical Analyses
• Dynamic Closed-Course Study Experimental Design and Statistical Analyses

NCHRP Report 1085 is accompanied by a slide presentation summarizing the project and a technical memorandum outlining potential implementation avenues for state DOTs and other transportation agencies. These materials are available on the TRB report website and can be found by searching for “NCHRP Research Report 1085.” Finally, the proposed language for consideration by AASHTO, “Proposed Updated Language: AASHTO Guidelines for the Selection and Application of Vehicle Markings and Warning Lights on Roadway Operations Vehicles and Equipment,” is available for download at https://onlinepubs.trb.org/onlinepubs/nchrp/05-24/ProposedLanguageforGuidelines.docx.

PUBLICATION INFO

114 pages |  8.5 x 11 |  DOI: https://doi.org/10.17226/27475