Effect of Concrete Pavement Surface Texture on Traffic Safety: Longitudinal or Transverse Tines?

Longitudinally tined (LT) concrete pavement surfaces were shown to produce less noise than transversely tined (TT) ones, making them more desirable where traffic noise may be an issue, if the two textures are shown to have equivalent safety performance. The present effort focused on rural freeway crashes between 1991 and 1998. This guaranteed the presence of high speeds and absence of various factors unrelated to pavement texture that affect safety, such as traffic signals, cross-street traffic, etc. The Wisconsin Department of Transportation uses TT portland cement concrete (PCC) surfaces. California provided the only substantial database for LT PCC. Climatic differences between Wisconsin and California were addressed by using hourly precipitation and travel data to calculate wet pavement crash rates for each of the two states. No statistically significant difference in the risk for wet pavement accidents vs. dry pavement accidents was identified between the two pavement textures (2.25 times higher risk on wet pavements for TT vs. 2.39 times for LT pavements). The database comprised 72.6 hundred million vehicle miles of travel (HMVM) in Wisconsin and 510 HMVM in California.