Warning Equipment

Information for a Class D license

Vehicle Size

Maximum Width- 8 feet for most vehicles. Load shall not project more than 6 inches beyond the width of the body. 

8 feet-six inches for buses

Maximum Height- 13 feet 6 inches for all vehicles. Some overpasses have less clearance than 13’6″.

Maximum Length- 40 feet for any single vehicle. (including load)

65 feet for truck-tractor and trailer combination.

Limits do not apply to auto carriers, trailers hauling poles or piling, or trailers hauling logs when operating during daylight hours, as these vehicles are subject to special rules.


Contents must not be allowed to drop, shift, leak or otherwise escape.

The load must be securely fastened so the covering, or load does not become loose, or in any manner a hazard to other motorists.

A load must not extend more than 4 feet to the front of the vehicle, or more than 8 feet beyond the rear of the vehicle except:

Poles, piling, and logs may project 15 feet beyond the rearmost part of the trailer.

If a load extends for 4 or more feet past the bed or body of any vehicle, a red flag 12 inches square must be attached to the extreme rear of the load during daylight hours. The entire area of the flag must be visible. At night, a red light must be attached to the extreme rear of the load and visible for at least 500 feet to the sides and rear.

Maximum speed for any vehicle in most states is 70 m.p.h., except:

When pulling or towing another motor vehicle the speed limit is 45 m.p.h.

School buses are limited to 35 m.p.h. when frequently stopping to load or unload children.

Following Distances

Rural highways outside business or residential areas, drivers of motor trucks must not follow within 400 feet of one another except to pass.
Also, high beam headlights must be dimmed no less than 500 feet from oncoming traffic, and 200 feet of a vehicle being followed.

Fire Extinguishers

Vehicles transporting passengers for hire must be equipped with at least a 2-BC type fire extinguisher.
Tow trucks must be equipped with at least one 4-BC type fire extinguisher.
Motor vehicles transporting explosives must have one 10-BC or better type fire extinguisher.
Every truck must have a device “mudflap” to minimize the spray or splash of water or mud or loose road surface material to the rear.

Warning Equipment

Passenger Buses and Freight carrying vehicles must carry
-Three flares, three electric red lanterns, or three red portable reflectors.
-Two 12 inch square red cloth flags with standards.

Trucks carrying explosive, flammable liquid, compressed gases, or using compressed gas as a fuel must use red electric lanterns or red emergency reflectors only. Flares or fuses are not allowed. 

One signal must be placed 100 feet behind the 100 feet forward of the truck. Each of these 2 signals must be in the center of the lane or shoulder. The third signal must be on the traffic side of the truck 10 feet to the front or rear.


All trailers or semi-trailers with a gross weight of 3000 pounds or more must be equipped with brakes adequate to stop and hold it. Care should be used to avoid excessive use of brakes on long downgrades. Drivers should use engine compression as the principal means of controlling speed on long grades. If your brakes should fail on the level road, you should downshift and use engine compression to slow down.

Trailers and Towed Vehicles

When towing another vehicle, the drawbar or other connection shall be of sufficient strength to pull all towed weight and shall not exceed 15 feet.


Distance can exceed 15 feet when transporting poles, pipes, machinery, or other objects which cannot be readily dismembered.


A rear view mirror must reflect a view of the highway for a distance of 200 feet to the rear regardless of the load of the vehicle.


1.Tail lights must be visible for 1000 feet to the rear.
2.Reflectors must be visible from 600 feet.
3.Clearance lights must be visible from 500 feet.