Federal Highway Administration State Planning and Research Funding
Illinois Department of Transportation
Federal Subaward from Univ of Illinois at Urbana-Champaign
Neal Hawkinshawkins@iastate.edu email >
Associate Director, InTrans
Omar Smadismadi@iastate.edu email >
About the research
Pavement markings provide critical guidance to motorists, especially under dark (un-lit) conditions. However, the ability to see pavement markings on a wet, rainy night is problematic given that the presence of water considerably decreases pavement marking retroreflectivity.
This project evaluated the performance of several all-weather pavement marking products in an effort to provide guidance on their use on Illinois Department of Transportation (IDOT) roadways. In addition, a laboratory evaluation was completed in an effort to simulate degradation mechanisms of these pavement markings so that future all-weather materials can be evaluated in a timely manner within the laboratory rather than on public roadways.
The study found that only 15 percent of the all-weather products provided a retroreflectivity of 50 millicandelas per meter squared per lux (mcd/m²/lux), which is noted as (mcd) within the report, under continuous wetting conditions.
The laboratory evaluation showed some promise for the dry retroreflectivity performance given that data variability was low and there the correlation was good initially with the field data. The correlation was not as good, however, as the markings aged, and correlation in wet conditions was not good either.