It was manufactured with a reinforced internal structure that allows the tire to be driven on after air pressure loss. When air pressure leaves the tire due to a puncture or other road damage, the structure maintains the tire's optimal shape and withstands the weight of the vehicle and its passengers. In this manner, the tire can be driven on for 50 miles up to the speed of 50 mph. This prevents the driver from being stranded on the side of the road when damage occurs. Run flat tires are usually made for vehicles without space for spare tires and they cannot be mixed with regular tires on the same vehicle.