An ignition interlock device is a breath-testing device that is installed in a vehicle and is connected to the ignition, horn and headlights. To start the vehicle, a driver must blow into the device without registering a blood alcohol concentration (BAC). MoDOT doesn't install, remove or maintain ignition interlock devices. Please contact an approved provider for more information.
MoDOT Motor Carrier Services helps carriers get the information, credentials and permits needed to start and continue a carrier business in Missouri. We also enforce safety and economic regulations to help make our highways safe and fair places to earn a living.