A run-flat tire is a pneumatic vehicle tire that is esigned to resist the effects of deflation when punctured, and to enable the vehicle to continue to be driven at reduced speeds (up to 90 km/h or 55 mph), and for limited distances of up to 100 miles (160.9 km), or even 200 miles (321.8 km) depending on the type of tire. First patented in 1892 (Victorian Age), run-flat tires were re-developed in 1978 and offered as an option in the 1990s mainly for two-seat sports cars with little room for spare tires and jacks. They have grown in popularity for other vehicles, such as high-end luxury cars, because of their safety and convenience, costing only double the price of sports tires.