Michelin offers two kinds of run-flat tires that continue to function safely after losing air pressure. The first is the Michelin ZP, or Zero Pressure, line and the second is the Michelin PAX system.
The Michelin ZP line includes rubber inserts between the layers of cord that enable the tire to maintain structural integrity even in the event of the loss of air pressure.
The Michelin PAX system is a special wheel that has a support ring that the tire can rest on after losing air pressure. This shifts the burden to the wheel and away from the tire. However, the set up is incompatible with traditional tires, is often more expensive and is only available for a limited number of cars, as of 2015.
All run-flat technologies temporarily maintain car integrity with a flat tire, but the problem always requires immediate attention.