# Title 37 — Department of Transportation

## Article 37-06 — Multiple Vehicle Combinations

## Chapter 37-06-04 — Combinations of Two, Three, or Four Vehicles - Over Seventy-Five Feet

Ninety-Seven Feet
### § 37-06-04-01. Authorized combinations of vehicles exceeding seventy-five feet.

The following combinations of vehicles exceeding seventy-five feet [22.86 meters] in overall length
may be operated on those highways described in section 37-06-04-02:
1. Any combination of two units.
2. A truck-tractor and semitrailer may draw a trailer or semitrailer converted to a trailer by use of
a converter dolly and fifth wheel. This combination of vehicles is commonly referred to as an
A-train or a double bottom.
3. A truck-tractor and semitrailer may draw a semitrailer. This combination of vehicles is
commonly referred to as a B-train.
4. A truck properly registered and designed to legally carry a gross weight of more than
twenty-four thousand pounds [10886.22 kilograms] may draw two trailers or semitrailers
provided both trailers or semitrailers are designed to legally carry gross weights of more than
twenty-four thousand pounds [10886.22 kilograms], provided both trailers or semitrailers are
equipped with safety chains and brakes adequate to control the movement of and to stop and
hold such trailers or semitrailers. The brakes shall be designed as to be applied by the driver
of the truck from the cab. The brakes shall be designed and connected so that in case of an
accidental breakaway the brakes shall be automatically applied on the trailer or semitrailer that
breaks loose.
5. A combination of four units consisting of a truck-tractor, semitrailer, and two trailers. A
semitrailer used with a converter dolly is considered to be a trailer. This combination of
vehicles is commonly referred to as triple trailers or a triple bottom.
History: Effective October 1, 1983; amended effective December 1, 1985; March 1, 1999.
General Authority: NDCC 39-12-04
Law Implemented: NDCC 39-12-04
### § 37-06-04-01.1. Authorized combinations of vehicles exceeding seventy-five feet, not to

exceed ninety-seven feet.
The following combinations of vehicles exceeding seventy-five feet [22.86 meters], but not
exceeding ninety-seven feet [29.56 meters] in overall length may be operated on those highways
described in section 37-06-04-02.
1. A motor vehicle may draw up to three motor vehicles attached to the towing motor vehicle by a
saddlemount. In such a mount, the front wheels of the towed motor vehicle are mounted upon
the bed of the towing vehicle, with any other towed motor vehicles being mounted in a like
manner on the preceding motor vehicle.

2. A motor vehicle may draw up to three motor vehicles with no more than one smaller vehicle
fully mounted on the frame of the first or last vehicle in the saddlemount. The drawn vehicles
shall each be connected by a saddlemount. This combination of vehicles is commonly referred
to as a drive-away saddlemount with fullmount vehicle transporter combination.
History: Effective July 1, 2008.
General Authority: NDCC 39-12-04
Law Implemented: NDCC 39-12-04; 49 USC 31111
### § 37-06-04-02. Routes of operation.

Authorized combinations of vehicles may be operated on all four-lane divided state highways and
on those state highways designated by the director as shown on special highway maps available at the
highway patrol and department of transportation headquarters in Bismarck and at the respective district
offices in Williston, Minot, Devils Lake, Grand Forks, Fargo, Valley City, Jamestown, and Dickinson.
Authorized combinations of vehicles may travel off the designated system a distance of ten miles [16.09
kilometers] on a state highway for the purpose of procuring food, fuel, repairs, obtaining sleeping
quarters (rest), or going to a terminal or points of loading or unloading.
History: Effective October 1, 1983; amended effective November 1, 1987; July 1, 2008.
General Authority: NDCC 39-12-04
Law Implemented: NDCC 39-12-04
### § 37-06-04-03. Minimum power requirement.

The power unit shall have adequate power and traction to maintain a minimum speed of fifteen
miles [24.14 kilometers] per hour on all grades.
History: Effective October 1, 1983.
General Authority: NDCC 39-12-04
Law Implemented: NDCC 39-12-04
### § 37-06-04-04. Weight distribution by trailer weight.

1. In any three-unit combination, the lighter trailer must always be operated as the rear trailer
except when the gross weight differential with the other trailer does not exceed five thousand
pounds [2267.96 kilograms].
2. In any four-unit combination, the lightest trailer must always be operated as the rear trailer.
The other two trailers must be arranged as provided in subsection 1.
History: Effective October 1, 1983.
General Authority: NDCC 39-12-04
Law Implemented: NDCC 39-12-04
### § 37-06-04-05. Signing requirement.

The last trailer or vehicle in any three-unit or four-unit combination must have a "LONG LOAD" sign
mounted on the rear. The "LONG LOAD" sign must be a minimum twelve inches [30.48 centimeters] in
height and sixty inches [152.4 centimeters] in length. The lettering must be eight inches [20.32
centimeters] in height with one-inch [2.54-centimeter] brushstrokes. The letters must be black on yellow
background.
History: Effective October 1, 1983; amended effective May 1, 1999; July 1, 2008.
General Authority: NDCC 39-12-04
Law Implemented: NDCC 39-12-04

### § 37-06-04-06. Weather restrictions.

Movements of combinations of vehicles authorized for operation under this chapter are prohibited:
1. When road surfaces, due to ice, snow, slush, or frost present a slippery condition which may
be hazardous to the operation of the unit or to other highway users;
2. When wind or other conditions may cause the unit or any part thereof to swerve, to whip, to
sway, or fail to follow substantially in the path of the towing vehicle; or
3. When visibility is reduced due to snow, ice, sleet, fog, mist, rain, dust, or smoke.
The North Dakota highway patrol may restrict or prohibit operations during periods when in its judgment
traffic, weather, or other safety conditions make travel unsafe.
History: Effective October 1, 1983.
General Authority: NDCC 39-12-04
Law Implemented: NDCC 39-12-04
