Updated minimum retroreflectivity levels for traffic signs.

This report includes an updated set of recommended MR levels for traffic signs based on recent developments in vehicle headlamps, vehicle types/sizes, nighttime driver needs, and newer sheeting materials. The updated MR levels are also based on more robust computer modeling of retroreflective sheeting performance.The development of minimum retroreflectivity (MR) levels for traffic signs has been going on for more than two decades, but it was significantly accelerated in 1984 when the Center for Auto Safety petitioned the Federal Highway Administration (FHWA) to establish retroreflectivity standards. During the past decade, several sets of recommended MR levels for traffic signs have been proposed. However, these preliminary recommendations have been based on a headlamp-beam pattern that represents vehicle design from the midto late-1980s. Vehicle headlamps have changed significantly since then. Other significant changes also have prompted the need to update the recommended MR levels for traffic signs before FHWA initiates the rulemaking process.This report includes an updated set of recommended MR levels for traffic signs based on recent developments in vehicle headlamps, vehicle types/sizes, nighttime driver needs, and newer sheeting materials. The updated MR levels are also based on more robust computer modeling of retroreflective sheeting performance.The development of minimum retroreflectivity (MR) levels for traffic signs has been going on for more than two decades, but it was significantly accelerated in 1984 when the Center for Auto Safety petitioned the Federal Highway Administration (FHWA) to establish retroreflectivity standards. During the past decade, several sets of recommended MR levels for traffic signs have been proposed. However, these preliminary recommendations have been based on a headlamp-beam pattern that represents vehicle design from the midto late-1980s. Vehicle headlamps have changed significantly since then. Other significant changes also have prompted the need to update the recommended MR levels for traffic signs before FHWA initiates the rulemaking process.Federal Highway Administration, Office of Safety Research and Development, McLean, Va.Mode of access: Internet.Author corporate affiliation: Texas Transportation Institute, College StationAuthor corporate affiliation: Battelle Memorial Institute, Columbus, Ohio""June 2003"--Cover"July 2003"--Technical report documentation pageSubject code: NDGSubject code: PMHF*CISubject code: CISubject code: RCGEFSubject code: LC