Idaho frost law restrictions 2021.

2021 Idaho winter frost/spring thaw laws and seasonal weight restrictions.

During the spring months when warmer temperatures cause the road surface to break up and generally deteriorate, the highways most affected are restricted to lower axle weights and speed restrictions.
The District will sign and mark affected state highways the day before the weight and/ or speed restrictions are in effect. The weight and/or
speed restrictions will be enforced the day after the Districts sign and mark the state highway.
On those sections of highways which are posted for legal weight, or to less than legal weight, trucks and buses weighing 10,000 pounds or
more will be restricted to 30 mph in critical areas. Speed zones will be marked with red and yellow markers. A red marker will mean speed
is restricted to 30 mph and a yellow marker will mean that legal speed can be resumed.
For information on operating restrictions for state highways posted for spring breakup limits or to check on a route of travel for construction
restrictions etc., go to and the trucking page.
It is important for the trucking industry to cooperate and comply with the load and speed limits. If compliance with the load and speed limits
are adhered to, the need for future, more restrictive, limits may be alleviated. Excessive violations may lead to the implementation of more
restrictive limits.

Live map.

This is a excellent reference and resource point for Idaho chain laws and basic seasonal weight restriction information.


See also:

Tire chain laws.
Tire chain laws by location.
Trucking regulations.
Federal bridge formula.
Exemptions from seasonal restrictions.


2021 Idaho State Shipping Regulations

2021 Idaho state DOT shipping laws, rules, regulations and limitations for oversize and heavy-haul trucking permits. Pilot car requirements.

Please share your knowledge of Idaho regulations with others below.


The great state of Idaho seal.

Idaho oversize permits, heavy-haul trucking companies and pilot cars.

Locate oversize, heavy-haul trucking companies and pilot cars:

Idaho pilot cars and truck escorts for hire.
Idaho oversize and heavy-haul trucking companies for hire.
Idaho oversize and heavy-haul trucking permits.

Do I need a trucking permit? Legal load limits.

Idaho maximum load limits until a trucking permit is required:

Length: A 75’ length is the legal limit for any combined truck and trailer in transport.
Width:  A maximum of 8’ 6” wide.
Height: A maximum of 14’
Weight: A maximum of 80,000 lbs. total (GVW) with no more than 14,000 lbs. on the steer axle and 20,000 lbs. on any other single axle.
Overhang: 4’ in front of trailer and no more than 10’ from the rear axle of trailer to the end of load.

Routine oversize and heavy haul trucking permits.

These maximum dimensions/weights are considered routine oversize or heavy-haul trucking permits in Idaho:

Length: 110’ on 2 lane roads and 115’ on 4 lane roads.
Weight: 5 axles 112,000 6 axles 118,000
Width: 16’
Height: 14’6”

Idaho superloads.

Lights, safety flags and warning signs for heavy haul and oversize loads.

Required safety markings, safety flags, warning lights for heavy haul and oversize loads:

When pilot cars or escort vehicles are required.

Heavy-haul or oversize loads may be required to be accompanies by a escort vehicle or pilot car if:

Length: Over 100’ 2 Lanes requires 1 car.  Over 115’ Interstate requires 1 car.
Width: Over 12’1” 2 Lanes requires 1 car., Over 15’1” 4 Lanes requires 1 car.
Height: Over 16’ requires 1 car.

Pilot cars/escort vehicle certifications and requirements.

Pilot car or escort vehicle mandatory operator certifications and vehicle requirements:

Legal travel times for oversize and heavy haul loads.

Travel times and restrictions for heavy-haul and oversize loads:

Travel permitted from ½ hour before sunrise to ½ hour after sunset.  If 10’ wide or less, travel is permitted 24/7.

Idaho DOT contact information and notes.

Idaho DOT office and permit contact information:

How to apply for trucking permits:
Idaho Transportation Department
3311 W State St
Boise. ID

208-334-8420 Phone
800-662-7133 Phone within Idaho
Basic fee is $13.00
Permit is valid for 5 days
Idaho State Trucking information website:

Port of Entry Information.

Hollister: 21 miles south of Twin Falls 208-3322-7844.
East Boise: 11 miles east of Boise 208-334-3272.
Marsing: 6 miles south of US 55/US 95 208-896-4814.
Lewiston: 1 mile east of Lewiston 208-799-4824.
Huetter: 2 miles east of Coer d’Alene 208-769-1551.
Bonner’s Ferry: (Moyle Jct.) Jct. of US 95 & US 2 208-267-2486.
Haugan:  15 miles east of state line 406-678-4257.
Sage Junction: 2 miles north of Roberts 208-228-3636.
Inkom: 8 miles south of Pocatello 208-775-3322.
Cottrell:  8 miles south of Twin Falls 208-349-5650.

Ports of entry references.

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 Idaho State DOT Permits office before commencing movement.


Idaho oversize trucking permits

Idaho oversize trucking permits

Idaho oversize and over-weight trucking permits. Do it yourself – DIY easy!

oversize trucking permits as well as over-weight

Save money DIY trucking permits. Oversize and over-weight.

You can save your trucking company a considerable amount of money today fairly easy.

Looking for ways to save money? Oversize and over-weight trucking permits is a good way to start. With all of the new technology here to stay state DOT offices have found ways to cut spending costs by automating the trucking permit process by streamlining the process online. While the Idaho DOT is not as advanced as many states they still have created an online interface for dealing with oversize and over-weight trucking permits which works to the advantage of the dispatcher or driver for OS and OW trucking  companies looking to save money. The process is pretty simple and can save you a bundle in the overall picture – something that permit processing companies aren’t exactly jumping with joy to let you know since their livelyhood depends on your continued business of ordering permits. It used to be that the service was worth it but they’re just too easy to obtain these days and we can not only point you in the right direction but show you how.

You can have your oversize or over-weight trucking permit approved in just a few hours.

Not only that it’s pretty easy too. Idaho DOT has a pretty interesting program for issuing single trip permits for oversize and over-weight trucking companies. You simple answer a few questions over the phone and you are ready to go. For annual trucking permits you create an online account. As long as you pay for each permit as you go with a debit card you are good to go. If you wish to continually deal with Idaho and be billed for their trucking permits you can put up a $1000.00 bond – THIS IS NOT REQUIRED. So let’s get started:

  1. For single trip permits simply have the answers to these questions ready and call then number below.
  2. If you wish to create an account for annual permits that information is here.
  3. submit the permit and relax as the state is working on getting it approved.

Not so bad at all right? Now if you get it the hang of doing your own trucking permits all of the time you will be on your way to saving your trucking company thousands if not tens of thousands of dollars every year. Online technology has made it much easier for the driver or dispatcher to obtain their own oversize and over-weight trucking permits so you might as well enjoy the savings while you can and move on. It’s just another spoke in the wheel for OS/OW trucking. If you liked this article and would like to share it simply click the button above. If you have comments that you’d like to leave for our other visitors please use the form below to do so and thank you for visiting our site.