La. Admin. Code tit. 73, § I-503 - Legal Limitations

A. Weights

1. The maximum legal axle weights on interstate highways are:

a. single axles-20,000 pounds;

b. tandem axles-34,000 pounds;

c. tridem axles-42,000 pounds;

d. quadrum axles-50,000 pounds.

2.

a. Axle variances of 2,000 pounds for single axles and 3,000 pounds for tandem, tridum, and quadrum axles are allowed on noninterstate highways. Therefore, the maximum legal weights on noninterstate highways are:

i. single axles-22,000 pounds;

ii. tandem axles-37,000 pounds;

iii. tridum axles-45,000 pounds;

iv. quadrum axles-53,000 pounds.

b. Exception. Weight limits for vehicles with tandem axles carrying forest products in their natural state shall be 40,000 pounds.

3. The maximum legal weight on a tire is 650 pounds per inch width of tire.

4. The sum of the legal axle weights on a vehicle or combination of vehicles is its legal gross weight. But regardless of the number and type of axles, the maximum legal gross weight of any vehicle or combination of vehicles (except a combination with a tridum or quadrum axle) is 80,000 pounds.

5. Regardless of the number and type of axles, the maximum legal gross weight of any combination of vehicles which has a tridum or quadrum axle is 83,400 pounds interstate highways, 88,000 pounds noninterstate highways.

6. Vehicles may not exceed their licensed gross weight. Maximum licensed gross weight is equal to the maximum legal gross weight.

B. Bridge Formula

1. In accordance with the applicable provisions of the Administrative Procedure Act, R.S. 49:950 et seq., the Louisiana Department of Transportation and Development adopted a rule regarding implementation of the "Bridge Formula" as it applies to vehicles which operate on the interstate highways of the state of Louisiana. The action was taken pursuant to Act 686 of the 1987 session of the Louisiana Legislature.

2.

a. The Bridge Formula set forth in 23 U.S.C. 127 and in R.S. 32:386 applies to all vehicles except:

i. Type 6 (five axle configurations with one single axle and two sets of tandem axles) carrying one of the commodities listed in §503. B.2 b;

ii. Type 8 (six axle configuration with one single axle, and one tridum axle) carrying one of the commodities listed in §503. B.2 b;

iii. Type 10 (double-bottom) carrying one of the commodities listed in §503. B.2 b

b. The above types of vehicles must be carrying the following commodities in their bulk or natural state:

i. forest products;

ii. sand;

iii. gravel;

iv. agriculture products; or

v. lumber.

C. Width

1. The maximum width of any vehicle except a bus is 96 inches.

2. Vehicles between 96-102 inches shall have reasonable access, not to exceed 10 miles, from designated highways or the interstate system, to be allowed to facilities for food, fuel, repairs, and rest, unless otherwise prohibited.

3. The maximum legal width of a bus is 8 feet 6 inches.

4. The load on any vehicle shall not project more than 12 inches beyond the width of its body. The overall width of vehicle and load shall not exceed the legal dimensions as described above.

D. Height. The maximum legal height of a vehicle is 13 feet 6 inches.

E. Length

1. The maximum legal length of any single vehicle is 40 feet.

2. The maximum legal length of a combination of vehicles on highways other that the designated truck route shall be 65 feet.

3. The maximum legal length of a semi-trailer on the designated truck route shall be 59 feet 6 inches.

4. The maximum legal length of any trailer, semi-trailer portion of a combination of vehicles shall not exceed 30 feet.

5. Semi-trailer or trailer components that exceed 30 feet (exclusive of all legal overhang) must obtain an oversize permit, but are restricted to designated truck routes.

6. Exception. The maximum legal combination length of specialized equipment (i.e., auto transporters, boat transporters, dromedary units) is 75 feet.

7. Exception. The maximum legal length of the load carried by a combination of vehicles transporting forest products in their natural or treated state is 65 feet plus 1 foot additional tolerance in length. However, these vehicles may operate only during daylight hours and must display a 1 foot square red flag on the rear of the load.

8. Exception. Sportsmen coaches or vehicles obviously used solely for recreational purposes and registered therefore, may tow a combination of no more than two vehicles and shall not exceed 70 feet in total length.

F. Projecting Loads

1. Equipment that is permanently attached to and cannot be readily removed from a vehicle is not considered load if the vehicle meets state safety standards and is licensed for use on state highways, and if any projection beyond the vehicle is at least 6 feet above the surface of the highways.

2. A vehicle or combination of vehicles with a projecting load cannot exceed the total length limitations for that vehicle or combination of vehicles. In addition:

a. a load cannot project more than 4 feet beyond the front of a single vehicle or 4 feet in front of the foremost vehicle of a combination of vehicles;

b. a load cannot project more than 8 feet beyond the rear of the bed or body of a single vehicle or the rear vehicle of a combination of vehicles.

3. Exception. The load on the rear vehicle of a combination of vehicles transporting forest products in their natural state cannot project more than 20 feet beyond the rear of the bed or the back of the rear tire of the vehicle, whichever is further from the cab, and the load must clear the pavement by at least 2 feet. When the rear projection is more than 15 feet, the vehicle may operate only during daylight hours and must display a red flag at least 1 foot square on the rear of the projection.

4. Exception. Vehicles transporting poles or piling cannot project more than 15 feet and must clear the pavement by at least 2 feet.

G. Twin Trailer Combinations

1. A combination of vehicles cannot consist of more than two vehicles.

a. Exceptions:

i. combinations of a truck-tractor and two trailers;

ii. truck-tractor and two semi-trailers; or

iii. truck-tractor, semi-trailer, and trailer.

2. These twin trailer combinations are subject to route limitations.

a. They may operate only over the interstate system and the designated truck routes within a reasonable access of 10 miles.

3. Household goods carriers shall have unrestricted access for loading and unloading purposes only, unless otherwise prohibited.

4. No combination of vehicles operated on any parish road shall consist of more than two vehicles.

a. Exceptions

i. A vehicle having no more than two axles may tow any combination of two vehicles, provided the combination of vehicles does not exceed 65 feet.

ii. A vehicle having no more than two axles and owned and/or operated by a manufacturer or dealer of boats may tow two boat trailers.

H. Trailers and Towed Vehicles

1. Drawbars and other connections must be strong enough to pull all the towed weight and cannot exceed 15 feet between vehicles.

2. Exception. The connection between any two vehicles transporting poles, pipe, machinery, or other objects of a structural nature which cannot be readily dismembered may exceed 15 feet.

3. If the connection between a vehicle and a towed vehicle is a chain, rope, or cable, then a red flag, at least 1 foot square, must be displayed on the connection between sunrise and sunset, and a red light visible under ordinary atmospheric conditions for at least 500 feet must be displayed on the connection between sunset and sunrise.

4. Exception. Truck-tractors being transported by the triple saddle mount method.

a. The combination of vehicles must be equipped with the necessary lights and signals in accordance with state and federal laws and regulations.

b. The rear wheels of the second, third, and fourth truck-tractors must be equipped with adequate splash guards or mud flaps.

I. Farm Vehicles and Equipment

1. Farm vehicles and equipment, except draglines and bulldozers, being operated and/or transported for bona fide agricultural purposes or the transportation of farm vehicles and equipment to be used for normal farm purposes by persons transporting such farm equipment or machinery for distances not to exceed 50 miles from the point of origin shall be exempt from the requirements for width, height, length, and for trailers and towed vehicles.

2. Such farm vehicles may use any public highways other than those designated as part of the National System of Interstate and Defense Highways during the period from 30 minutes after sunrise until 30 minutes before sunset without obtaining a special permit from the secretary, or from any other agency or department of the state or political subdivisions, provided that such machinery or equipment being shipped by persons to be used for normal farm purposes shall be equipped with front and rear reflector lights and with a blinking hazard light clearly visible from the front and rear.

J. Care of Vehicle Load

1. The load on a vehicle cannot drop, leak, or otherwise escape from the vehicle. The load must be securely fastened so as to prevent the load or any covering from becoming loose, detached, or in any manner a hazard to other users of the highway.

2. Loose Material- dirt, sand, gravel, or other material that is capable of blowing or spilling from a vehicle as a result of movement or exposure to air, wind currents, or weather, but shall not include agricultural products in their natural state or wood chips.

3. Any load of loose material as defined above being transported by a commercial hauler shall be covered in such a manner as to prevent the load from blowing, spilling, or dropping from the vehicle.

Notes

La. Admin. Code tit. 73, § I-503

Promulgated by the Department of Transportation and Development, Office of Highways, LR 7:410 (August 1981), amended LR 9:254 (April 1983), amended by the Office of Weights, Measures and StandaLR rds, 22:120 (February 1996).

AUTHORITY NOTE: Promulgated in accordance with R.S. 32:2 et seq.