ALABAMA
Total length: 57 feet; trailer length: 28 feet 6 inches; motorhome length: 45 feet; width: 8 feet 6 inches (excluding mirrors and safety equipment, and appurtenances up to 6 inches attached to a motorhome, travel trailer, self-propelled camper or house car, truck camper, or RV); height: 13 feet 6 inches.
ALASKA
Total length: 75 feet; trailer length: 53 feet; motorhome length: 45 feet; width: 8 feet 6 inches (excluding appurtenances, equipment up to 3 inches, turn signals, handholds, splash and spray suppressant devices, load-induced tire bulge, retracted RV awnings, AC power outlets and exhaust fans); height: 15 feet.
ARIZONA
Total length: 65 feet; trailer length: 28.5 feet; motorhome length: 45 feet; trailer width: 8 feet (8 feet 6 inches on certain roads); motorhome width: 8 feet 6 inches (excluding appurtenances up to width of rear view mirrors); height: 13 feet 6 inches (14 feet on designated roads).
May pull 2 units if the middle unit has a 5th wheel and brakes and has a weight equal to or greater than the rear unit; the rear unit is 3,000 lbs. or more and is equipped with brakes.
ARKANSAS
Total length: 53 feet 6 inches; trailer length: 28 feet; motorhome length: 40 feet; width: 8 feet 6 inches (excluding safety equipment); height: 13 feet 6 inches.
CALIFORNIA
Total length: 65 feet (up to 75 feet in certain circumstances); trailer length: 28 feet 6 inches; motorhome length: 40 feet (38 feet for a single-axle fifth wheel travel trailer; 40 feet for 2- or more axle fifth wheel travel trailer); width: 102 inches (excluding safety equipment and RV appurtenances up to 6 inches); height: 13 feet 6 inches (14 feet on designated roads).
COLORADO
Total length: 75 feet (excluding safety equipment and extension devices used for loading beyond the front or rear ends, used in combination for transporting automobiles and boats); trailer length: 45 feet; motorhome length: 45 feet; width: 8 feet 6 inches (excluding RV appurtenances up to 6 inches); height: 13 feet (14 feet 6 inches on designated roads)(14 feet 6 inches on all roads effective August 10, 2016).
CONNECTICUT
Total length: 65 feet (excluding the transportation of boats under 4,000 lbs.); trailer and motorhome length: 40 feet; width: 8 feet 6 inches (for trailers, excluding safety equipment up to 3 inches and the transportation of boats under 4,000 lbs.; for motorhomes, excluding appurtenances up to 6 inches); height: 13 feet 6 inches (excluding appurtenances up to 6 inches).
DELAWARE
Total length: 60 feet (65 feet for an RV towing a vehicle); trailer and motorhome length: 45 feet; width: 8 feet 6 inches for trailers, 8 feet for motorhomes (excluding safety equipment); height: 13 feet 6 inches.
DISTRICT OF COLUMBIA
Total length: 55 feet (excluding safety equipment and energy conservation devices); trailer and motorhome length: 40 feet; width: 8 feet (8 feet 6 inches on certain roads with certain combinations); height: 13 feet 6 inches.
FLORIDA
Total length: 65 feet; trailer length: 48 feet; motorhome length: 40 feet; width: 8 feet 6 inches (excluding safety equipment and appurtenances); height: 13 feet 6 inches.
GEORGIA
Total length: 100 feet; trailer length: 53 feet (56 feet for boat transporters); width: 8 feet 6 inches (excluding mirrors); height: 13 feet 6 inches (14 feet on designated roads).
HAWAII
Total length: 65 feet; trailer and motorhome length: 45 feet; width: 9 feet; height: 14 feet.
IDAHO
Total length: 75 feet (excluding carry devices necessary for safe and efficient operation); trailer length: 48 feet (excluding carry devices necessary for safe and efficient operation); motorhome length: 45 feet; width: 8 feet 6 inches; height: 14 feet.
ILLINOIS
Total length: 60 feet; trailer length: 53 feet (excluding safety equipment and energy conservation devices); motorhome length: 45 feet (excluding energy absorbing bumpers and mirrors); width: 8 feet 6 inches (excluding safety devices on interstates and mirrors;, for motorhomes, appurtenances up to 6 inches on roadways at least 11 feet in width); height: 13 feet 6 inches.
INDIANA
Total length: 60 feet (excluding boat transporters); trailer length: 28 feet 6 inches; motorhome length: 45 feet; width: 8 feet 6 inches (for motorhomes, excluding appurtenances up to the width of rear view mirrors); height: 13 feet 6 inches.
IOWA
Total length: 65 feet; trailer length: 53 feet (45 feet for travel trailers); motorhome length: 45 feet; width: 8 feet 6 inches (excluding safety equipment up to 6 inches); height: 13 feet (excluding safety equipment up to 6 inches).
KANSAS
Total length: 65 feet; trailer length: not specified; motorhome length: 45 feet; width: 8 feet 6 inches (excludes mirrors, equipment up to 3 inches, turn signals, handholds, splash and spray suppressant devices, load-induced tire bulge, and appurtenances up to the width of rear view mirrors); height: 14 feet.
KENTUCKY
Total length: 65 feet; trailer and motorhome length: 45 feet; trailer width: 8 feet (excluding safety equipment); motorhome width: 8 feet 6 inches (excluding appurtenances and safety equipment up to 6 inches); height: 13 feet 6 inches.
LOUISIANA
Total length: 65 feet; trailer length: 30 feet; motorhome length: 45 feet; width: 8 feet 6 inches (excluding safety equipment and for motorhomes, safety equipment up to 6 inches); height: 13 feet 6 inches (14 feet on designated roads).
MAINE
Total length: 65 feet; trailer length: 48 feet; motorhome length: 45 feet; width: 8 feet 6 inches (excluding mirrors, turn signals, and appurtenances up to 6 inches); height: 13 feet 6 inches.
MARYLAND
Total length: 55 feet (65 feet for travel trailers and boat transporters); trailer length: 35 feet; motorhome length: 40 feet (45 feet on interstates); width: 8 feet 6 inches (excluding retractable awnings, and safety equipment and energy conservation devices up to 3 inches); height: 13 feet 6 inches.
MASSACHUSETTS
Total length: 65 feet (excluding appurtenances); trailer length: 33 feet (excluding appurtenances); motorhome length: 45 feet (excluding appurtenances); width: 8 feet 6 inches (excluding mirrors, safety equipment, turn signals, handholds, splash and spray suppressant devices, load-induced tire bulge, and retracted RV awnings); height: 13 feet 6 inches.
MICHIGAN
Total length: 65 feet; trailer length: 28 feet 6 inches; motorhome length: 45 feet; width: 8 feet 6 inches (excludes appurtenances for motorhomes); height: 13 feet 6 inches.
MINNESOTA
Total length: 75 feet (70 feet if an RV combination); trailer and motorhome length: 45 feet (excluding bumpers up to 6 inches and aerodynamic devices); width: 8 feet 6 inches (excluding rear view mirrors and load securement devices up to 3 inches, and for motorhomes, excluding appurtenance up to the width of rear view mirrors); height: 13 feet 6 inches.
MISSISSIPPI
Total length: not stated; trailer length: 53 feet; motorhome length: 45 feet (excluding bumpers); width: 8 feet 6 inches (excluding safety equipment, for motorhomes, excluding appurtenances up to width of rear view mirrors); height: 13 feet 6 inches.
MISSOURI
Total length: 65 feet; trailer and motorhome length: 45 feet (excluding bumpers for motorhomes); width: 8 feet 6 inches (excluding safety equipment and clearance lights and required accessories, and for motorhomes, excluding appurtenances up to width of rear view mirrors); height: 13 feet 6 inches (14 feet on designated roads).
MONTANA
Total length: 65 feet; trailer length: not specified; motorhome length: 55 feet; width: 8 feet 6 inches (excluding safety equipment and appurtenances up to the width of the rear view mirror); height: 14 feet.
Passenger vehicles less than 2,000 lbs. GVW may tow 1 trailer; this combination shall not exceed 65 feet. Three-unit combinations shall not exceed 65 feet. Three-unit combinations permitted if rear unit is equipped with breakaway brakes.
NEBRASKA
Total length: 65 feet (excluding bumpers); trailer and motorhome length: 40 feet (excluding bumpers); width: 8 feet 6 inches (excluding safety equipment and for motorhomes, appurtenances up to 6 inches); height: 14 feet 6 inches.
NEVADA
Total length: 70 feet; trailer and motorhome length: not specified; width: 8 feet 6 inches (for trailers excluding lights or devices up to 6 inches, door handles, hinges, cable cinchers and chain bundlers up to 3 inches; for motorhomes, excluding mirrors, safety equipment, and lights and awnings or hardware up the width of rear view mirrors); height: 14 feet.
NEW HAMPSHIRE
Total length: 53 feet; trailer length: not stated; motorhome length: 45 feet (excluding bumpers); width: 8 feet 6 inches (for motorhomes, excluding appurtenances up to 6 inches); height: 13 feet 6 inches.
NEW JERSEY
Total length: 62 feet, 65 feet with a camping trailer, fifth wheel trailer, or park trailer; trailer length: 53 feet, 45 feet for motorhomes, 28 feet as part of a combination; width: 8 feet 6 inches (only on certain roads, excluding safety equipment up to 6 inches); height: 13 feet 6 inches.
NEW MEXICO
Total length: 65 feet (excluding bumpers); trailer length: 40 feet; motorhome length: 45 feet; width: 8 feet (excluding safety equipment up to 6 inches; for motorhomes, excluding appurtenances up to 6 inches); height: 14 feet.
NEW YORK
Total length: 60 feet (excluding bumpers); trailer length: 48 feet; motorhome length: 40 feet (excluding bumpers); width: 96 inches (excluding safety equipment up to 6 inches; for motorhomes, excluding awnings over 7.5 feet from the ground and up to 6 inches on the right and 4 inches on the left); height: 13 feet 6 inches.
NORTH CAROLINA
Total length: 60 feet (excluding bumpers); trailer length: 40 feet (excluding bumpers); motorhome length: 45 feet (excluding mirrors and bumpers); width: 8 feet 6 inches; height: 13 feet 6 inches.
A boat or boat trailer with a width between 102 and 120 inches is permitted to be towed as long as the boat or trailer is equipped with two operable amber lamps on the widest point to clearly mark outside dimensions. The towing of a boat or boat trailer 114 inches to 120 inches in width may take place only during daytime.
NORTH DAKOTA
Total length: 75 feet (excluding safety equipment, energy conservation devices, and approved length exclusion devices); trailer length: 53 feet (excluding safety equipment, energy conservation devices, and approved length exclusion devices); motorhome length: 50 feet (excluding safety equipment, energy conservation devices, and approved length exclusion devices); width: 8 feet 6 inches (excluding appurtenances up to 6 inches and safety equipment up to 3 inches); height: 14 feet.
OHIO
Total length: 65 feet (excluding mirrors, safety equipment, carrying devices, and loading equipment up to 24 inches beyond the rear); trailer length: not stated; motorhome length: 45 feet (excluding mirrors, safety equipment, carrying devices, and loading equipment up to 24 inches beyond the rear); width: 8 feet 6 inches (excluding mirrors, safety equipment, turn signals, handholds, splash and spray suppressant devices, load-induced tire bulge, marker lamps, fender extension, automotive covering devices, tarp and tarp hardware, and tie-down assemblies up to 3 inches); height: 13 feet 6 inches.
OKLAHOMA
Total length: 65 feet; trailer length: 40 feet; width: 8 feet 6 inches (excluding safety equipment, retracted RV awnings up to 8 inches, and appurtenances up to 4 inches); height: 13 feet 6 inches.
OREGON
Total length: 65 feet; trailer length: 40 feet; motorhome length: 45 feet; width: 8 feet 6 inches (for motorhomes, excluding appurtenances up to 4 inches); height: 14 feet.
PENNSYLVANIA
Total length: not stated; trailer length: not stated; motorhome length: 40 feet; width: 8 feet 6 inches (excluding mirrors, and sunshades and tarps up to 6 inches); height: 13 feet 6 inches.
RHODE ISLAND
Total length: not stated; trailer length: 40 feet; motorhome length: 45 feet; width: 8 feet 6 inches (excluding safety equipment, for motorhomes, appurtenances, for trailers, non-cargo-carrying appurtenances); height: 13 feet 6 inches.
SOUTH CAROLINA
Total length: 53 feet (excluding safety equipment, energy conservation devices, loading equipment, compressors, and fuel-saving equipment on the front); trailer length: 40 feet (excluding safety equipment, energy conservation devices, loading equipment, compressors, and fuel-saving equipment on the front); motorhome length: 45 feet (excluding safety equipment, energy conservation devices, loading equipment, compressors, and fuel-saving equipment on the front); width: 8 feet 6 inches (excluding safety equipment, for motorhomes appurtenances up to 6 inches); height: 13 feet 6 inches.
SOUTH DAKOTA
Total length: not stated; trailer and motorhome length: 45 feet (excluding bumpers); trailer width: 8 feet 6 inches (excluding safety equipment, for motorhomes appurtenances up to 6 inches); height: 14 feet.
TENNESSEE
Length: not stated; width: 8 feet (excluding safety equipment, appurtenances, and retracted RV awnings up to 6 inches); height: 13 feet 6 inches.
TEXAS
Total length: 65 feet; trailer length: 28 feet 6 inches; width: 8 feet; height: 14 feet.
UTAH
Total length: 65 feet; trailer length: 48 feet; motorhome length: 65 feet; width: 8 feet; height: 14 feet.
VERMONT
Total length: 75 feet; trailer length: not stated; motorhome length: 46 feet; width: 8 feet 6 inches (excluding safety equipment and appurtenances up to 6 inches); height: 13 feet 6 inches.
VIRGINIA
Total length: 65 feet (excluding safety equipment, energy conservation devices, and steps and handholds for entry); trailer length: 28 feet 6 inches; motorhome length: 45 feet (excluding bumpers); width: 8 feet 6 inches (excluding mirrors, and for trailers appurtenances); height: 13 feet 6 inches.
WASHINGTON
Total length: 75 feet; trailer length: not stated; motorhome length: 40 feet (excluding bumpers, safety equipment, energy conservation devices, compressors, and fuel saving equipment on the front); width: 8 feet 6 inches (excluding mirrors and for motorhomes, appurtenances up to 4 inches); height: 14 feet.
WEST VIRGINIA
Total length: 65 feet (excluding bumpers); trailer length: 40 feet (excluding bumpers); motorhome length: 45 feet (excluding bumpers); trailer width: 8 feet (excluding safety equipment); motorhome width: 8 feet 6 inches (excluding safety equipment); height: 13 feet 6 inches.
WISCONSIN
Total length: 70 feet; trailer and motorhome length: 48 feet (for trailers, excluding bumpers, stake pockets, air deflectors, ad refrigeration units); width: 8 feet 6 inches (for trailers, excluding appurtenances up to the width of rear view mirrors); height: 13 feet 6 inches.
WYOMING
Total length: not stated; trailer and motorhome length: 60 feet; width: 8 feet 6 inches (excludes appurtenances up to the width of rear view mirrors); height: 14 feet.
PUERTO RICO
Height from the ground must not exceed 13 feet, 6 inches; length, including load, must not exceed 40 feet; and width must not exceed 8 feet, 6 inches.
The overall length of 2 vehicles coupled together may not exceed 75 feet, including load.
Weight: Overall GVW may not exceed 110,000 lbs.
source: drivinglaws.aaa.com/tag/trailer-dimensions/