This reinforces the structure in order to enable the tire's limited, temporary performance after air pressure loss. In other words, the tire is able to be driven for 50 miles, at 50 mph once air pressure leaves the tire due to a puncture or some other damage. As a result, the vehicle will not be stranded on the side of the road. Run flat tires should not be mixed with regular tires on the same vehicle, as they have a heavier internal structure.