Siping
Siping is a process of cutting thin slits across a rubber surface to improve traction in wet or icy conditions.
Siping was invented and patented by John Sipe in the 1920s. Sipe worked in a slaughterhouse and grew tired of slipping on the wet floors. He found that cutting slits in the tread on the bottoms of his shoes provided better traction than the uncut tread.
The process was not applied to vehicle tires on a large scale until the 1950s, when superior tread compounds were developed that could stand up to the siping process. On roads covered with snow, ice, mud, and water, sipes usually increase traction. A US patent to Goodyear claimed sipes improve tire traction as well, and tend to close completely in the tire “footprint” on the road. A 1978 study by the US National Safety Council found siping improved stopping distances by 22 percent, breakaway traction by 65 percent, and rolling traction by 28 percent on glare ice.