An airless tire is a rubber tire that has extra-thick side walls and tread area. This allows the tire to remain operable even with no air pressure. While the ride is somewhat harsher than when aired to specification, the airless tire prevents the operator from having to stop and change a flat tire. The run-flat or airless tire is used on high-performance vehicles where there is no room for a spare tire to be carried.
Several manufacturers have developed an airless tire to be sold under their brand; however, the demand for the product was never very high. Television commercials showing an airless tire being driven at highway speed with a hole sawed into the side wall only reinforced the notion that this was a very stiff tire that would offer a stiff ride. The appeal for the sports-car market was that these vehicles rode rough anyway. In this marketplace, the airless tire would not feel strange or out of place.
The run-flat tire design was first fostered by the NASCAR racing series. These race cars run what is called an inner liner. This is essentially a tire in a tire that allows the driver to maintain control of a car when a tire blows at racing speed. By converting the technology to street-driven tires, the airless tire was conceived and manufactured. This did not come without protest from some groups.
Law enforcement agencies all around the world questioned the use of an airless tire on a street-driven car. The most effective method law enforcement agencies have to immobilize a speeding vehicle that will not stop for patrol vehicles is the spike strip. The spike strip is placed in the path of the fleeing vehicle—when making contact with the strip, the vehicle's tires are flattened, causing it to come to a stop. A vehicle equipped with an airless-tire system would suffer no ill effect from making contact with a spike strip, hence the dilemma.
While still available in some areas, the sale of the airless rubber tires are limited to only high-performance vehicles, and the sales are monitored by agencies that track the use of such tires. In the event of a high-speed chase with a vehicle equipped with run-flat tires, running the vehicle's license will alert pursuing officers of the presence and use of the tires. This will allow information to assist the officers in choosing alternate methods of stopping the vehicle.