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Interpretation ID: nht89-1.90

TYPE: Interpretation-NHTSA

DATE: May 16, 1989

FROM: Billy Mohr -- Commander, Support Section, Motor Carrier Division, Michigan Department of State Police

TO: Donald W. Vierimaa -- Truck Trailer Manufacturers Association

TITLE: None

ATTACHMT: Attached to letter dated 6/1/94 from John Womack to Donald W. Vierimaa (VSA S103(a)), letter dated 8/9/93 from Donald W. Vierimaa to John Womack, and letter dated 5/12/89 from Donald W. Vierimaa to Billy Mohr

TEXT:

I have reviewed the S. 108 DOT interpretations you have provided. The 53 foot trailers have been allowed in Michigan for several years. The Michigan Legislature was specific in its requirements for use of trailers over 50 feet in length. The requirements are those recommended by the University of Michigan, Transportation Research Institute. The National Highway Traffic Safety Administration has not notified the State of Michigan that the requirement of an additional "clearance lamp" as near to the top of the semitrailer as practicable is preempted by Section 103 (d) of the National Traffic and Motor Vehicle Safety Act of 1966. Be advised that the lamp is not a marker lamp as mentioned in 1.7 of the DOT interpretations.

The statute that covers height, length and underride protection is within the Motor Vehicle Code, Act. 300 P.A. 1949 as amended. I cannot provide you with a copy of the Michigan Motor Vehicle Code, as it must be purchased from the Michigan Department of State. However I am including Section 719 as a part of this letter. Section 719 is as follows:

"Sec. 719. (1) Except as provided in subsection (2), a vehicle unloaded or with load shall not exceed a height of 13 feet 6 inches. The owner of a vehicle which collides with a lawfully established bridge or viaduct shall be liable for all damage and injury resulting from a collision caused by the height of the vehicle, whether the clearance of the bridge or viaduct is posted or not.

(2) A truck, truck tractor, semitrailer, or trailer manufactured on or after July 27, 1978, shall not be used to transport flammable liquids, in bulk, having a flash point at or below 70 degrees Fahrenheit, if the truck, truck tractor, semitrailer, or trailer exceeds 11 feet 8-1/2 inches in height. However, safety equipment and those appurtenances which are required by state law, when added to a vehicle, may cause the vehicle height to exceed 11 feet 8-1/2 inches, but shall not cause the vehicle height to exceed 13 feet 6 inches. A person who violates this subsection is guilty of a misdemeanor.

(3) A vehicle, except a truck tractor, trailer, or semitrailer, including load, or articulated buses operated by a local public transit system funded by Act No. 51 of the public Acts of 1951, being Sections 247.651 to 247.674 of the Michigan Compiled Laws, shall not exceed a total length of 40 feet. The total length of a semitrailer operating in a truck tractor and semitrailer combination shall not exceed 53 feet, including load. All

semitrailers longer than 50 feet shall have a wheelbase of 40.5 feet plus or minus 0.5 feet, measured from the kingpin coupling to the center of the rear axles or to the center of the tandem axle assembly if equipped with 2 axles. Articulated buses operated by a local public transit system funded by Act No. 51 of the Public Acts of 1951 may operate with a maximum length of 65 feet. A combination of truck tractor, semitrailer, and trailer, or truck and semitrailer or trailer, or a combination of truck tractor and 2 semitrailers, including load, shall not exceed a total overall length of 59 feet except as provided for on routes designated and approved by the state transportation department and by local authorities with respect to highways under their jurisdiction on which a person may operate a combination of a truck tractor, semitrailer, and trailer or a truck tractor and 2 semitrailers with no limit on the overall combination length, if the length of each semitrailer or trailer including load does not exceed 28-1/2 feet. The state transportation department and local authorities with respect to highways under their jurisdiction may designate highways where the overall length of a truck and trailer or semitrailer shall not exceed 65 feet. A truck tractor and semitrailer combination with a semitrailer length longer than 50 feet shall not be allowed to operate with more than 2 axles on the semitrailer. All truck tractor and semitrailer combinations with a semitrailer length longer than 50 feet shall travel exclusively on highways designated by the appropriate road authority. City, village, or county authorities shall have the option of prohibiting stops within their jurisdictions unless the stop occurs along appropriately designated routes, or is necessary for emergency purposes or to reach shippers, receivers, warehouses, and terminals along designated routes. A trailer or semitrailer in actual and lawful use in this state on December 1, 1982, may be operated in this state for the life of the vehicle in a combination with other vehicles in actual and lawful use in this state on December 1, 1982, if the combination was of legal length under the law of this state immediately preceding January 24, 1984. In calculating the length of a trailer or semitrailer under this subsection, the length shall be based on the cargo carrying portion of the vehicle only, including load. A truck tractor or other motor vehicle shall not haul more than 1 trailer and 1 semitrailer or more than 2 semitrailers in combination at any 1 time, except that a farm tractor may haul 2 wagons or trailers or garbage and refuse haulers may, during daylight hours, haul up to 4 trailers for garbage and refuse collection purposes, not exceeding in any combination a total length of 55 feet at a speed of not to exceed 15 miles per hour. In determining the length of a vehicle or a vehicle combination under this subsection, the length shall not be considered to include safety and energy conservation devices including, but not be limited to, impact absorbing bumpers, rear view mirrors, turn signals lamps, marker lamps, steps and hand holds for entry and egress, flexible fender extensions, mud flaps, or splash and spray suppressant devices; load induced tire bulge; refrigeration or heating units; or air compressors. A device shall be excluded from a determination of length only if it is not designed or used for the carrying of cargo.

(4) If a combination of 2 semitrailers is pulled by a truck or truck tractor, a fifth wheel connecting assembly which conforms with motor carrier safety rules promulgated by the department of state police pursuant to the motor carrier safety act of 1963, Act No. 181 of the Public Acts of 1963, as amended, being sections 480.11 to 480.21 of the

Michigan Compiled Laws, shall be used on each semitrailer.

(5) A train of vehicles or a vehicle operated alone shall not carry a load extending more than 3 feet beyond the front of the train of vehicles or vehicle.

(6) A motor vehicle, trailer, or semitrailer whose frame or body extends more than 36 inches beyond the rear of its rear axle and is more than 30 inches above the roadway shall not be operated on the highways of this state unless equipped with a fender or bumper on the extreme rear of the frame or body. The bumper shall extend downward from the rear of the frame or body to within 30 inches of the roadway and be of substantial construction. In addition to the requirements of subsection (7), no vehicle which is required by federal law to have an underride guard of not more than 22 inches above the roadway shall be operated upon the highways of this state without such an underride guard.

(7) A truck tractor and semitrailer combination with a semitrailer length longer than 50 feet whose frame or body extends more than 36 inches beyond the rear of its rear axle and is more than 30 inches above the roadway shall not be operated on the highways of this state unless equipped with an underride guard on the extreme rear of the frame or body. The underride guard shall meet all of the following requirements:

(a) Provide a continuous horizontal beam having a maximum ground clearance of 22 inches, as measured with the vehicle empty and on level ground.

(b) Extend to within 4 inches of the lateral extremities of the trailer on both left and right sides.

(8) A truck tractor and semitrailer combination with a semitrailer length longer than 50 feet shall not be operated on the highways of this state at the times specified in section 684 unless equipped with all of the following lamps and reflectors, in addition to any other lamps and reflectors required under this act:

(a) Two side marker lamps which display an amber light, 1 on each side of the semitrailer, located at 1/2 the distance from the front to the rear of the semitrailer.

(b) Two reflectors which reflect an amber light, 1 on each side of the semitrailer, located at 1/2 the distance from the front to the rear of the semitrailer.

(c) Two clearance lamps, 1 on each side of the semitrailer, located at 1/2 the distance from the front to the rear and as near to the top of the semitrailer as practicable.

(9) A lamp required under subsection (8) shall be lighted at the times specified in section 684 and shall be visible when lighted at a distance of 500 feet from the side of the semitrailer on which it is mounted. A reflector required under subsection (8) shall be visible at the times specified in section 684 from all distances from 50 to 500 feet from the semitrailer when directly in front of lawful upper beams of headlamps.

(10) Notwithstanding any other provisions of this section, a person may operate a combination of truck tractor, semitrailer, and trailer, or truck tractor and semitrailer or trailer designed and used exclusively to transport assembled motor vehicles or bodies, recreational vehicles, or boats, which does not exceed a total length of 65 feet. The load on the combination of vehicles may extend an additional 3 feet beyond the front and 4 feet beyond the rear of the combination of vehicles. Retractable extensions used to support and secure the load that do not extend beyond the allowable overhang for the front and rear shall not be included in determining the length of a loaded vehicle or combination of vehicles.

(11) A combination of vehicles shall not have more than 11 axles.

(12) Notwithstanding any other provisions of this section, a number of motor vehicles, wholly or partially assembled, may be transported over the highways of this state in combination, utilizing 1 tow bar or 3 saddle mounts with full mount mechanisms and utilizing the motive power of 1 of the vehicles in combination. The combination shall not exceed the maximum length of 65 feet for the transportation of assembled motor vehicles, and the vehicles in the combination shall be adequately and securely fastened together in compliance with regulations of the state and of any federal agency having jurisdiction over the transportation. If motor vehicles are towed by means of triple saddle mounts, the towed vehicles shall have brakes acting on all wheels which are in contact with the roadway. A combination exceeding 55 feet in length may be operated only on highways and routes approved and designated for that operation by the state transportation department and by local authorities with respect to highways under their jurisdiction.

(13) The total gross weight of a truck tractor, semitrailer, and trailer combination or a truck tractor and 2 semitrailers combination which exceeds 59 feet in length shall not exceed a ratio of 400 pounds per engine net horsepower delivered to clutch or its equivalent specified in the SAE handbook published by the society of automotive engineers, inc., (1977).

(14) Except as provided in subsection (2), a person who violates this section is responsible for a civil infraction. The owner of the vehicle may be charged with a violation of this section."

Your diagrams of trailers with pin setting measurements, marker lamps and underride protection is correct. However I want to point out that I cannot visualize a semitrailer such as you have on pages 4 and 5 where there would be less than 36 inches from the rear of the last axle to the rear of the semitrailer. There would be more than 9 feet from the pin to the front of the semitrailer.

If I can be of any further assistance regarding this matter, please contact me at 517/373-4910.