398.4—Driving of motor vehicles.

Service brakes, including trailer brake connections.
Parking (hand) brake.
Steering mechanism.
Lighting devices and reflectors.
Tires.
Horn.
Windshield wiper or wipers.
Rear-vision mirror or mirrors.
Coupling devices.
Fire extinguisher, at least one properly mounted.
Road warning devices, at least one red burning fusee and at least three flares (oil burning pot torches), red electric lanterns, or red emergency reflectors.
All such motor vehicles shall display a sign on the rear reading, “This Vehicle Stops at Railroad Crossings.”
[33 FR 19765, Dec. 25, 1968, as amended at 40 FR 44557, Sept. 29, 1975]