Diamond grooving on three Ohio highways significantly reduced wet-weather accident rates.
ODOT has specified longitudinal diamond grooving -- which helps reduce hydroplaning risks, increases drainage at the tire/pavement interface, and aids in vehicle control -- on concrete bridge decks since 2012. However, most of Ohio's state roadways are not concrete; they are asphalt or composite pavement.
The superior safety performance of grooving on bridge decks encouraged the department to use the technique on several sections of asphalt pavement, all located on high-speed roadways and tight curves where wet weather safety was a concern.
Read more about ODOT's use of longitudinal grooving on asphalt pavements.