If you are forced to stop your commercial motor vehicle on a highway or shoulder of a highway for anything other than necessary traffic stops, as the driver, you are required to warn others of your presence using the emergency warning devices kept on your unit.

In the event it is necessary to make an emergency stop or your vehicle becomes disabled:

  1. Immediately activate the hazard warning flashers. These should remain flashing until you have properly placed the unit’s emergency warning devices.
  2. If appropriate, move your vehicle as far off the road as possible to avoid being a hazard to other drivers.
  3. Within ten minutes of stopping, you are required to place the unit’s emergency reflective triangles or flares according to the instructions below:

Two-Lane Highway
If stopped on a two-lane highway, triangles or flares should be placed on the traffic side of the vehicle at 10 feet (approx. 4 paces) in the direction of approaching traffic; and in the middle of the lane or shoulder occupied by the vehicle at 100 feet (approx. 40 paces) in the direction of approaching traffic and 100 feet (approx. 40 paces) in the direction away from approaching traffic.

Divided Highway
If stopped on a divided or one-way highway, all triangles or flares should be placed in the direction of approaching traffic. One placed on the traffic side of the vehicle at 10 feet (approx. 4 paces); the others placed in the middle of the lane or shoulder occupied by the vehicle at 100 feet (approx. 40 paces) and 200 feet (approx. 80 paces).

Hills, Curves & Obstructions
If stopped within 500 feet of a curve, crest of a hill or other visual obstruction, triangles or flares should be placed according to the rules for two-lane or divided highways; however, the device nearest the obstruction should be placed at a distance of 100-500 feet from the vehicle so as to afford sufficient warning to other drivers.