The insert bears no vehicle load until the tire is punctured, at which point the load is transferred to the insert and vehicle movement may continue for a limited distance and speed.

• 这些单元在平时的时候不承载车辆的重量，只有当轮胎被打破了才会担负起承载的重任，这时候车辆的重量会转移到这些单元上，它们能支撑车辆继续以一定的速度移动一段距离。