2015 GMC Duramax Runaway

The only way to stop a run away is to remove the air supply, either by blocking the air supply, or displacing the oxygen with CO2 or Halon.

or install a Positive Air Shut-Off, can not get on a oil filed lease or plant site without one (in Alberta). they will shut air off to engine if it starts to race or can be tripped within the cab by the driver in an emergency. aught to be standard equipment on all diesel vehicles.