Roadway safety

While driver errors cause most traffic crashes, drivers’ errors are sometimes triggered by a vehicle mechanical problem or roadway problem. One-third of all crashes are roadway-related and half of those are weather-related. In the U.S., that amounts to killing 7,000 people every year and injuring another 800,000.

Anyone who has driven on snow- or ice-covered roads knows of the danger. One study of Iowa freeways found that snowstorms increase the crash rate an astounding 1,300%. Intuitively, we know that removing snow and ice from the pavement makes roads safer. Studies in Germany and the U.S. show consistently that traffic crash incidence – and severity – is reduced when salt is applied as part of a winter maintenance program; in the first four hours after salt is applied, a study done by Marquette University documented an 85% reduction in traffic crashes and an 88.3% reduction in injury crashes.

Our intuition also tells us why. Removing snow and ice restores a higher coefficient of friction. More friction means cars and trucks have more traction. More traction improves drivers’ ability to maintain control. Enhancing friction through winter snow and ice control, basically plowing and spreading salt, is one of the proven safety countermeasures of roadway safety plans. Thus, the focus of management attention is on preservation or restoration of roadway friction. New technologies to measure “road weather” and friction give snowfighters new information and tools to direct storm response activities. Yet many formal roadway safety plans ignore the crucial safety contributions of winter maintenance operations to achieving their crash reduction objectives.

Fortunately, the two primary areas of focus in progressive roadway agencies is the promotion of safety and efficient system operations. Snowfighting is a major solution in both areas.