Road surface Road debris is a
hazard to a serious
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. Road debris can be especially dangerous to
bicyclists, who may have to travel outside the
cycle lane and into traffic to avoid debris. Flooding can also occur if
storm drains and
street gutters are not kept clear of road debris and litter. Large quantities of water are sometimes thrown up from the road (road spray) by large vehicles, creating visibility problems for the drivers of oncoming, nearby, or following vehicles. Following vehicles may reduce the problem by slowing and increasing the
following/separation distance.
Headlights (or
fog lights) improve vehicle visibility for all drivers, including those dealing with the spray. Driving manuals advise against following vehicles too closely (
tailgating) in these hazardous conditions. Over time, road spray and gunk from [a bicycle's] brake pads coat the rim of the wheel, interfering with braking power. In
motorsport racing, road debris can cause loss of traction and subsequent crashes. Usually, the yellow
caution flag is used to indicate a track hazard, and the
pace/safety car will come out. Road debris can also cause other more specific problems and damage to vehicles. Rocks striking the
catalytic converter can cause the internal mat to break and clog the converter. Several
recalls have occurred due to road debris. The 2005
Scion TC's
wind deflector was recalled because of potential shatter from road debris impact. The 2004
Mitsubishi Endeavor was recalled in February 2010 when it was determined that a mixture of
road salt and road debris (mud) might be trapped between a reinforcing bracket and the
fuel filler pipe, causing corrosion. The 2001
Chevrolet C/K chassis cab truck was also recalled on discovery that road debris could strike and damage its
pressure relief valves.
Environmental Small debris particles and dust (primarily from tire wear and vehicle
exhaust particulates) constitute a significant problem when they are washed into the soil and leak into
groundwater reservoirs through
surface runoff, especially
urban runoff. Roadside
soil and
water contamination can result when the concentration of harmful constituents is high enough. The greater the
surface area of
synthetic rubber waste fragments, the greater the potential for breakdown into harmful constituents. For
leached tire debris, the potential
environmental impact of the ingredients
zinc and organic
toxicants has been demonstrated. Additionally, debris from lawns in local communities can flush into local waterways. There are currently some laws against blowing organic matter such as grass clippings into the roadway because of their potential toxic effect on the local waterways. Grass being high in nitrogen, which can accumulate in waterways and cause
algae blooms. An example of such laws can be seen in the City of Davenport, Iowa's Clean Air and Water Act. ==Prevention==