01620165

Component

https://doi.org/10.3141/2617-04

Guidelines for the provision of effective nighttime performance of overhead signs were developed. Relevant policies and guidelines with regard to sign lighting currently provide little useful information to determine when sign lighting is needed, and the reference material available to practitioners is out of date. Two complementary nighttime visibility studies were conducted, which were designed to produce results useful in developing updated guidelines for overhead sign visibility. The first was conducted on a closed course and investigated the legibility distances of three sign legend and background configurations under various sign lighting treatments. The second was conducted on the open road. It investigated the effects of sign luminance and visual complexity on the distance at which a driver can read overhead signs during a recognition task. The combined findings were used to develop revised guidelines designed to provide adequate nighttime visibility of overhead signs. The proposed guidelines are based on the needs of nighttime motorists and have been formatted specifically for AASHTO’s Roadway Lighting Design Guide, which is being updated. The revised chapter on roadway sign lighting was provided to the AASHTO task force responsible for revisions. The guidelines include a list of recommended retroreflective sheeting materials that can be used to meet nighttime driver needs for specific complexity levels.

01632438

17-04786

English

pp 27–34

2017

Transportation Research Record: Journal of the Transportation Research Board

9780309441667

Digital/other

Figures (4) ; Photos; References (4) ; Tables (2)

Illuminated traffic signs; Legibility; Luminance; Night visibility; Overhead traffic signs; Reflective signs

Highways; Operations and Traffic Management; Safety and Human Factors

PRP, TRIS, TRB, ATRI

Dec 8 2016 11:50AM

• Analyzing and Improving the Performance of Dynamic Message Sign Reporting Work Zone–Related Congestion
• Calibration of a Digital Camera for Rapid Auditing of In Situ Intersection Illumination
• Effect of Work Zone Lighting on Drivers’ Visual Performance and Perceptions of Glare
• Effects of Full Matrix Color Changeable Message Signs on Legibility and Roadway Hazard Visibility
• Field Evaluation of Pilot Vehicles and Portable Traffic Control Signals With and Without a Flagger
• Influence of Truck-Mounted Radar Speed Signs in Controlling Vehicle Speed for Mobile Maintenance Operations: Oregon Case Study
• Special-Color Pavement Marking for Highway Work Zones: Literature Review of International Practices
• Work Zone Coordination Software Tool
• Work Zone Impact Assessment Methods and Applications
• Work Zone Safety Performance: Comparison of Alternative Traffic Control Strategies