NCHRP: Guidelines for Lighting Overhead Signs

Lighting Overhead Signs
Client: National Cooperative Highway Research Program (NCHRP)
Audience: NCHRP managers and staff; state DOT research staff

This NCHRP’s Ready Results issue explores lighting for overhead signs in suburban and urban areas, where more complex road designs may make headlight illumination of overhead signs inadequate. In addition, there is little consensus and guidance about when sign lighting may be needed. NCHRP Report 828: Guidelines for Nighttime Visibility of Overhead Signs revises guidelines to include a visual complexity scale to help transportation agencies determine when nighttime sign lighting is necessary.