Administrative Rules of Montana › Department 18 - TRANSPORTATION › Chapter 18.8 - MOTOR CARRIER SERVICES DIVISION › Subchapter 18.8.5 - Overdimensional Permit Requirements › Rule 18.8.517 - SPECIAL VEHICLE COMBINATIONS

Current through Register Vol. 13, July 5, 2024
(1) A "special
				vehicle combination" is a truck-trailer-trailer combination of vehicles or
				truck tractor-semitrailer-trailer-trailer combination of vehicles as defined in
				statute and in 23 CFR 658, appendix C, April 1, 2015 edition. Copies of the
				regulations may be obtained from the U.S. Government Printing Office, 732 North
				Capitol Street, NW, Washington, DC 20401-00012, or at
www.gpo.gov
.
(2) No special vehicle combination may be
				operated without a valid overlength permit.
(3) Special overlength permits shall be
				issued to a specific truck or truck tractor and are nontransferrable, and may
				not be used for any other combination other than a "special vehicle
				combination" as defined in this rule.
(4) In addition to the special overlength
				permit, the operator must obtain all other necessary permits for travel in
				Montana.
(5) When a terminal is
				beyond a two-mile radius of an interchange on the interstate system, the
				Department of Transportation may authorize travel between the terminal and the
				interchange. The operator shall apply in writing to the Department of
				Transportation for authorization to travel outside the two-mile radius to reach
				a terminal. The written application must specify requested routing and show
				good cause why the travel is necessary.
(6) The Department of Transportation may
				restrict or prohibit travel of special vehicle combinations to specific routes,
				hours of operation, specific days, or seasonal periods, when adverse
				conditions, traffic, weather or other safety considerations make such operation
				unsafe or inadvisable. Special vehicle combinations shall not be dispatched
				during adverse weather conditions, as defined in section 392.14 of the Federal
				Motor Carrier Safety Regulations. If adverse weather or road conditions are
				encountered or if the road surface is icy or snowpacked, the driver of the
				special vehicle combination shall proceed to the next available exit or turnout
				and drop a trailer or wait for conditions to improve. If road or weather
				conditions are deemed sufficiently hazardous by the Montana Department of
				Transportation or the Montana Highway Patrol, they may instruct the special
				vehicle combinations to cease operations immediately until such hazardous
				conditions no longer exist.
(7) The
				following equipment requirements apply to special vehicle combinations:
(a) All trucks and truck tractors shall be
				powered to provide adequate acceleration ability and hill climbing ability
				under normal operating conditions, and to operate on level grades at speeds
				compatible with other traffic. The ability to maintain a minimum speed of 20
				m.p.h. under normal operating conditions on any grade over which the
				combination is operated is required.
(b) All trucks and truck tractors shall have
				adequate traction to maintain a minimum speed of 20 m.p.h. under normal
				operating conditions on any grade over which the combination is operated and to
				be able to resume a speed of 20 m.p.h. after stopping on any such grade and to
				negotiate all grades encountered.
(c) Each individual single and tandem axle
				shall have tires of the same size and construction (radial or nonradial) .
				Tires must be properly inflated for the load being carried, and shall meet the
				standards set forth in 49
				CFR section 393.75.
(d) All fifth wheels shall be clean and
				lubricated with a light duty grease. The fifth wheel shall be located in a
				position which provides adequate stability. The fifth wheel shall be heavy duty
				as required in 49 CFR
				section 393.70.
(e) Pick-up plates shall be of equal strength
				to the fifth wheel, as provided in
				49 CFR section
				393.70.
(f) The king pin shall be of a solid type and
				permanently fastened. Screw out or folding type king pins are
				prohibited.
(g) All hitch
				connections shall be of a no-slack type, preferably air actuated ram. Air
				actuated hitches, when used, must be isolated from the primary air transmission
				system.
(h) The drawbar length
				shall be the practical minimum consistent with weight distribution and
				clearances required between trailers for turning and backing
				maneuvers.
(i) Permanently attached
				trailer axles must be those designed for the width of the trailer.
(i) Truck-trailer-trailer combinations must
				have a minimum of six axles and a maximum of nine axles.
(ii) Truck
				tractor-semitrailer-trailer-trailer combinations must have a minimum of seven
				axles and a maximum of nine axles.
(j) All braking systems shall comply with
				state and federal requirements. In addition, fast air transmission and release
				valves shall be provided for all trailers, semitrailers, and converter dollies.
				A brake force proportioning valve may be provided on the steering axle.
				Indiscriminate use of engine retarder brakes is prohibited.
(k) Anti-sail mud flaps are required. If
				anti-sail mud flaps are not used, mud flaps and anti-spray and splash
				suppressant device systems are required.