Project Title: Impacts of Retroreflectivity on Sign Management, Maintenance, and Design

Sponsor: Texas Department of Transportation

Principle Investigator: Gene Hawkins

Research Staff: Paul Carlson

TTI Project Number: 417962

Start Date: 9/1/97

End Date: 8/31/02

Abstract: TxDOT's traffic signs represent a major capital investment. A recent TxDOT/TTI research project found that a computerized sign management system would be the most cost-effective means of implementing the minimum retroreflectivity values. This project will evaluate TxDOT's needs for such a system, evaluate the various options for implementing a system, establish how the system can be used to comply with the minimum retroreflectivity values, and provide TxDOT with the information needed to implement the system. Initial activities in evaluating computerized sign management systems have identified a need for a thorough assessment of TxDOT signing operations. This information is critical to the development of effective recommendations for a sign management system. The information is also important in light of recent TxDOT actions to upgrade all signing to current standards within three years. In addition to the minimum retroreflectivity values, advances in retroreflective sign s heeting in recent years have created concerns over sign performance. Two particular issues of concern are the impacts of brighter sheeting materials on sign legibility and the need for overhead sign lighting with the brighter materials. This project will also include preliminary investigations into the impacts of brighter sign sheeting and sign illumination on the legibility of traffic signs.