John Bullough, LRC senior research scientist and adjunct assistant professor presented two papers at the 90th Annual Meeting of the Transportation Research Board (TRB) of the National Academies in Washington, the week of January 24, 2011. These papers, co-authored by LRC Senior Research Specialist Nicholas Skinner, both address the increasing use of light-emitting diodes (LEDs) in roadway transportation applications.
The first paper, "Evaluation of Light-Emitting Diode Warning Beacons for Maintenance Vehicles," summarizes a recent LRC study of LED beacons on maintenance trucks. The LED beacon lights provide equivalent information for closure detection to other drivers, but use substantially less energy, allowing transportation agencies to turn trucks off rather than idle when parked at roadway work zones. This results in lower fuel costs and fewer greenhouse gas emissions. The TRB has recognized this paper as a "Practice-Ready Paper," meaning the results could be implemented immediately by departments of transportation.
The second paper, "Luminance Criteria and Measurement Considerations for Light-Emitting Diode Billboards," describes field measurements of LED and conventional billboards with the aim of identifying criteria for limiting the luminance of LED billboards to minimize distraction and glare from these signs, increasingly found along our nation's highways. The data from this study can be used to ensure that LED billboards will, at a minimum, be no higher in luminance than conventional billboards during both daytime and nighttime.
Abstracts of these papers can be found on the TRB website at the following links: