Remote Ignition Interrupter

The Remote Ignition Interrupter, or RII, is a safety feature for monster trucks that allow safety officials, if necessary, to shut the trucks ignition off with a handheld device to prevent serious crashes. The RII is argumentatively the most important safety feature of any monster truck show.

How it Works
During monster truck shows, safety members each use the RII, a handheld walk-talkie-like device equipped with buttons used to shut down the truck's ignition if the driver begins to become involved in a major crash or other dangerous situation where the driver cannot safely stop the truck himself. With the simple press of a button, the safety official can use the RII to instantly kill the truck's ignition, reducing the seriousness of the crash and potentially preventing the truck from hitting something or even someone.

There are three RII switches in total on a monster truck. The first one is on the handheld device held by the safety official. The second is inside the cab of the monster truck that the drivers are required to flip any time the truck crashes. The third switch is on the back of the truck, that safety officials will flip as soon as they reach the truck after a crash.

It is mandatory that during the monster truck racing competition, before each race, the RII is tested to make sure that it is working as it should be. After the two trucks are positioned to start the race, the trucks ignitions are shut off by the RII for a few seconds, and then they are fired back up by the drivers and then the race proceeds.