(a) The following vehicles shall not be operated upon any highway or bridge without a special written permit from the Commissioner of Transportation, as provided in § 14-270, specifying the conditions under which they may be so operated:

(1) A vehicle, combination of vehicle and trailer or commercial vehicle combination, including each such vehicle’s load, which is wider than one hundred two inches or its approximate metric equivalent of two and six-tenths meters or one hundred two and thirty-six-hundredths inches, including its load, but not including the following safety devices: Reasonably sized rear view mirrors, turn signals, steps and handholds for entry and egress, spray and splash suppressant devices, load-induced tire bulge and any other state-approved safety device which the Commissioner of Transportation determines is necessary for the safe and efficient operation of such a vehicle or combination, provided no such state-approved safety device protrudes more than three inches from each side of the vehicle or provided no such device has by its design or use the capability to carry cargo. Such permit shall not be required in the case of (A) farm equipment, (B) a vehicle or combination of vehicle and trailer loaded with hay or straw, (C) a school bus equipped with a folding stop sign or exterior mirror, as approved by the Commissioner of Motor Vehicles, which results in a combined width of bus and sign or bus and mirror in excess of that established by this subsection, (D) a trailer designed and used exclusively for transporting boats when the gross weight of such boats does not exceed four thousand pounds, (E) a recreation vehicle with appurtenances, including safety devices and retracted shade awnings, no greater than six inches on each side for a maximum allowance of twelve inches, or (F) a vehicle with an attached snow plow, provided the snow plow may not exceed one hundred forty-four inches in width; and

(2) A combination of truck and trailer which is longer than sixty-five feet except (A) a combination of truck and trailer or tractor and semitrailer loaded with utility poles, both trailer and semitrailer having a maximum length of forty-eight feet, utility poles having a maximum length of fifty feet and the overall length not to exceed eighty feet, (B) a trailer designed and used exclusively for transporting boats when the gross weight of such boats does not exceed four thousand pounds, (C) a tractor-trailer unit, (D) a commercial vehicle combination, (E) combinations of vehicles considered as specialized equipment in 23 C.F.R. § 658.13(e), as amended, having a maximum overall length of sixty-five feet on traditional automobile transporters, with the fifth wheel located on the tractor frame over the rear axle or axles, including low boys, or a maximum overall length of seventy-five feet on stinger-steered automobile transporters, excluding front and rear cargo overhangs, provided the front cargo overhang shall not exceed three feet and the rear overhang shall not exceed four feet. Extendable ramps used to achieve such three-foot front overhang and four-foot rear overhang shall be excluded from the measurement of overall length and shall be retracted when they are not supporting vehicles, or (F) a tractor equipped with a dromedary box operated in combination with a semitrailer which tractor and semitrailer do not exceed seventy-five feet in overall length.

(b) A special written permit may not be issued by the Commissioner of Transportation for a combination of vehicles consisting of a vehicle drawing a combination of three or more trailers or semitrailers, except any such combination engaged in the transportation of an indivisible load.

(c) The maximum length, including load, of a single unit vehicle shall be forty-five feet and the maximum length, including load, of the semitrailer portion of a tractor-trailer unit shall be forty-eight feet. A trailer greater than forty-eight feet and less than or equal to fifty-three feet in length, that has a distance of no more than forty-three feet between the kingpin and the center of the rearmost axle with wheels in contact with the road surface, may be operated on (1) unless posted otherwise, United States and Connecticut routes numbered from 1 to 399, inclusive, 450, 476, 508, 693 and 695 and the national system of interstate and defense highways, and (2) state and local roads for up to one mile from the routes and system specified in subdivision (1) of this subsection for access to terminals, facilities for food, fuel, repair and rest, and points of loading and unloading. The Commissioner of Transportation shall permit additional routes upon application of carriers or shippers provided the proposed additional routes meet the permit criteria of the Department of Transportation. Such length limitation shall be exclusive of safety and energy conservation devices, such as refrigeration units, air compressors or air shields and other devices, which the Secretary of the federal Department of Transportation may interpret as necessary for the safe and efficient operation of such vehicles, provided no such device has by its design or use the capability to carry cargo.

(d) Violation of any provision of this section shall be subject to a fine of five hundred dollars.