A method for controlling the operation of a vehicle prime mover based on the engagement status of one or more safety restraints of the vehicle. In various implementations the method comprises monitoring, via a RPM controller of the vehicle, an operational status of vehicle, monitoring, via the RPM controller, the engagement status at least one passenger safety restraint of the vehicle, and limiting, via the RPM controller, a rotational speed, e.g., revolutions per minute (RPM) of one or more prime mover of the vehicle when the vehicle is in a On operational status and the at least one safety restraint is in a disengaged status.