U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
Summary of Research Recommendations
- Investigate the use of video-based data acquisition and Fast Fourier Transform analysis for evaluation of the effectiveness (retroreflectivity degradation) of traffic control devices such as sign lettering, pavement markings, and delineators.
- Evaluate driver information needs at night, considering the following: safe stopping distance, navigational information needs, object in roadway informational needs, visibility needs in periphery (roadside) vision, probabilities of driver's attention being given to the various areas, the change in driver's scan for information habits with and without lighting (including just partial lighting) and also with variations in traffic volume, and the adequacy of small targets describing the overall visibility of the roadway (or providing the needed information).
- Quantify visibility differences in tunnels between positive- and negative-contrast lighting systems, especially in low tunnel ceilings with heavy truck traffic.
- Compare lighting systems using Information Theory (IT) (Fast Fourier Transforms) to discern differences between systems designed by the illuminance method, luminance method, and the STV method. Make field evaluations of pavement reflectance and make comparisons in the variation of information based on variations in pavement reflectance.
- Develop new bidirectional pavement reflectance distribution functions for all pavement types. Investigate variation in reflectivity due to spectral content of lamp. Evaluate Fast Fourier Transforms of pavement texture for correlation to pavement reflectance.
- Develop measuring techniques and standards for off-roadway glare sources. Research should include the effectiveness of adding or increasing roadway lighting levels to mitigate adverse effects of off-roadway lighting.
- Investigate the adverse effects of glare on pedestrians and bicyclists sufficient to allow designers to establish limits for such glare. Consider the benefits of the pedestrian's visibility versus the ability of the pedestrian to be seen.
Page last modified on November 7, 2014