Road debris, a form of road hazard, is debris on or off a road. Road debris includes substances, materials, and objects that are foreign to the normal roadway environment. Debris may be produced by vehicular or nonvehicular sources, but in all cases it is considered litter, a form of solid waste.
Road spray (or just spray) or tire kickup is road debris (usually liquid water) that has been kicked up, pushed out, or out from a tire.
Road debris can be caused by various factors, including objects falling off vehicles or natural disasters and weather, specifically wind, storms, tornadoes, hurricanes, etc.
Examples of road debris include:
Road debris is a hazard that can cause loss of vehicle control with damages ranging from a flat tire, vehicular rollover, penetration of the passenger compartment by the debris, or collision, with accompanying injuries or deaths.
In the year 2011, the National Highway Traffic Safety Administration's Traffic Safety Facts found that more than 800 persons were killed across America by "non-fixed objects" (a term that includes roadway debris). California had the highest number of total deaths for any state, while New Mexico had the greatest probability for death from a vehicle-debris crash in that year.
In 2004, a AAA Foundation for Traffic Safety study revealed that vehicle-related road debris caused 25,000 accidents—and nearly 100 deaths—each year. At highway speeds, even small debris can be deadly. On June 16, 1925, in the United States, a passenger train carrying German and American tourists from Chicago, Illinois to Hoboken, New Jersey struck debris washed into a road crossing and derailed during a heavy thunderstorm. Collision with road debris resulted in a solar vehicle accident at the World Solar Challenge 2007 in Australia.