Maximum width on interstates, highways, roads. Commercial or private.

What are the maximum legal length, width, height, and weight limits allowed on roads, highways, or Interstates?

The legal maximum length, width, height, and weight permitted to travel, tow, or transport on local roads, highways, or Interstates in the United States and Canada are as follows.

Maximum legal limits Standard Metric
Length: 65 feet. 19.8 meters.
Width: 8 feet, 6 inches. 2.6 meters.
Height: 13 feet, 6 inches. 4.1 meters.
Weight: 80,000 pounds. 36,287 kilograms.
Notes: Always verify state/provincial legal limits prior to movement/transport.

These rules pertain to single personal vehicles (towed or otherwise), commercial motor vehicles including semi-tractors, trailers, and buses. Mirrors and certain safety devices (such as flags, etc.) may be permitted to protrude a “reasonable” distance further. Always obtain official consultation about any protrusion(s) you may have by contacting your state/provincial DOT office prior to any movement. Local city/county roads may vary from the maximum length/width/height/weight limits governed by federal guidelines.

Exceptions:

Within the state of Hawaii commercial motor vehicles are permitted the following maximum width on all highways (unless otherwise posted on the road by sign): Standard: 9 feet or 108 inches. Metric: 2.74 meters or 274 centimeters.

These roads usually have signs posted that display the maximum legal width permitted without obtaining a special travel permit. You should always inquire about the maximum widths permitted by the governing body of the particular road prior to traveling on it in order to prevent a fine or worse. In some situations depending on the width of the vehicle or shipment size, a route survey will be required prior to being granted permission to travel.

Maximum width allowed.

Maximum width laws are created to protect motorists and public assets. Know the maximums.

The importance of setting maximum widths for vehicles.

Safety and protection of motorists and public property are the primary reasons regulations have been set for maximum vehicle length/width/height/weight limitations.

A standard was required based on the dimensions of the existing roads that would protect any/all persons operating a motor vehicle on highways, roads, and Interstates. It should be noted public property is placed at risk for damage as well. Should motorists accidentally hit one of the many existing obstructions such as guard rails, signs, traffic signal poles, etc. liability while ultimately is the motorists, if it is not reported the state is required to repair damages which then is passed on to the taxpayers in both the USA and Canada. So maximum widths were created to protect both human lives but public property as well.

Maximum width allowed

Maximum vehicle width permitted on highways. Image credit FHWA.

Noteworthy information:

“Federal width limits do not apply to special mobile equipment, which consists of self-propelled vehicles not designed or used primarily for the transportation of persons or property and only incidentally moved over the highways. Special mobile equipment includes the following, when moving under their own power: military or farm equipment; instruments of husbandry; road construction or maintenance machinery; and emergency apparatus, including police and fire emergency equipment. Federal rules do not require States to issue overwidth permits before allowing the operation of special mobile equipment. However, if States wish to allow other vehicles more than 102 inches wide (i.e. non-special mobile equipment) to operate on the NN, then States must issue special overwidth permits.” Reference Credit: FHWA website.

History:

“The Federal Government first enacted size regulations for CMVs with the passage of the Federal-Aid Highway Act of 1956. This Act provided a maximum vehicle width of 96 inches (2.44 meters) on the Interstate highway system. Subsequently, the Federal-Aid Highway Act of 1976 increased the allowable width for buses to 102 inches (2.6 meters). The Surface Transportation Assistance Act (STAA) of 1982 extended the same width requirement of 102 inches to commercial trucks. At the same time, the STAA expanded the highway network on which the Federal width provision applied from the Interstate to the National Network (NN) of highways.” Reference Credit: FHWA website.

 

Related links:

See regulations for maximum load limitations.
Learn what a route survey is.
The maximum length allowed on roads, highways, and interstates.
Maximum legal load sizes.
Multi-state and regional permits.

 

 

Maryland State Shipping Regulations

2021 Maryland state shipping regulations, limitations, and laws for oversize and heavy haul trucking.

 If you would like to share your knowledge with others please do so at the bottom of this page.

Maryland oversize regulations.

Seal of the great state of Maryland.

Legal Loads.

Length: 65’ (48’ trailers) (53’ allowed on Interstate only with 41’ to the kingpin max), and not more than 4′ set back from the front of the trailer to the kingpin
Overhang: 3’ front and 6’ rear maximum.
Weight: GVW 80,000
Tandem: 34,000
Width: 8’ on non-designated highways – 8’6” on designated highways.
Height: 13’ 6”

Routine trucking permits.

Length: 120’
Weight: Less than 120,000 (non-Interstate) to 150,000 (Interstate), single – 27,000 lbs., tandem – 52,000 lbs., tridem – 63,000 lbs.
Width: 16’
Height: 14’ 6” – high pole required. (any height over 13′ 6″ cannot be permitted on a flatbed). Over 14′-6″ now requires a route survey.
Notes: Loads exceeding any of these weight/dimensions are classified as super loads. Over 120,000 pounds gross on any non-Interstate route is a superload.

When you are required to have pilot cars.

Length: Over 120’
Weight: Over 110,000 lbs.
Width: Over 13’ requires 1 pilot car in front. Over 14’ requires 1 pilot car in front and 1 pilot car in the rear.
Height: Over 16’.

Travel times and restrictions.

Times that you are not allowed to travel within the state of Maryland with oversize or heavy haul loads:

Daylight hours are defined as one-half hour after sunrise and one-half hours before sunset. You may not travel on Sunday. Saturday travel is permitted in till noon. Maryland state DOT has different curfews that have to be followed in areas with high traffic densities. Typically these hours are from 9 AM in till 3:30 PM. No travel is usually allowed between these hours. The state of Maryland has many toll bridges and tunnels that may charge additional fees. You should contact the Maryland Transportation Authority (US-50:410–537–6601, I95: 410–537–1150, FC Key Bridge: 410–537–7600). Traveling on any of these toll roads bridges or tunnels. Always be sure to check your physical permit for curfew times. Especially if you are in excess of 45 gross tons 100 feet in length or over 12 feet wide. If you are over 14 feet by you will not be permitted to travel between the hours of 9 AM and 3:30 PM on any highway. Travel is not permitted on any of the following holidays: New Year’s Day, Good Friday, Memorial Day, Independence Day, Labor Day, Thanksgiving Day, and Christmas Day. The Maryland state DOT permit office for oversize and heavy haul loads is closed on the above-mentioned holidays as well as Martin Luther King Day, Columbus Day, election day and is also close on the day after Thanksgiving but travel is not restricted on these days.

No movements across any toll facilities are permitted from noon Friday until 9:00 am Monday including I-95 from Baltimore to the Delaware state line. Over 12′ wide or over 92,000 pounds can only travel 9:00 am to 3:30 pm (and Saturday until Noon) when on the Capital Beltway I-495/I-95 and Baltimore Beltway I-695. If 14′ wide or more, travel is only permitted from 9:00 am to 3:30 pm (and Saturday until Noon on any roads/highways).

Maryland DOT contact information.

Information and links for oversize and heavy haul shippers:

Maryland State Highway Administration
Office of Traffic Safety, Oversize, and heavy haul division
Hauling Permits Unit
7491 Connelley Dr.
Hanover, MD  21076

E-mail: mdmotorcarrier@sha.state.md.us or haulingpermits@sha.state.md.us
Phone: 410-582-5727, 800-846-6435 or 800-543-4564
Fax: 410-787-2863 or toll free fax: 800-945-3416

Hours: Monday thru Friday 7:30 am to 4:30 pm (closed noon to 1 o’clock).
NOTES: Single trip permits are valid for 5 days. Also, Maryland has a pretty good manual you can view here.
Baltimore City: Baltimore permits routes into or out of Dundalk Marine Terminal are included with the Maryland state permit provided the dimensions are under 120,000 pounds, 12′ wide, 14′-6″ high, and 85′ long. Loads with other Baltimore destinations or origins, or loads exceeding these dimensions have to be ordered separately from Baltimore City, which is usually slow. Count on a 24-hour wait.

 

The information contained in these pages is research information primarily for use by oversize and overweight trucking company drivers, dispatchers, and pilot car companies. While every effort is put into maintaining the accuracy of this information you must absolutely verify this information with the Maryland State DOT Permits office before commencing movement.

 

 

maryland-state