Its reinforced sidewalls support the weight of the vehicle and the passengers for 50 miles up to the speed of 50 mph in case of air pressure loss, allowing the driver to safely arrive at a destination where they can fix or change the tires. Thanks to this, the driver will not be stranded on the side of the road with a flat tire. Run flat tires are made for vehicles that don't have space for spare tires. They cannot be mixed with regular tires on the same vehicle, as their construction is heavier.