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Idaho trucking rules

Fees, CDL costs, weight and size limits, chain laws and new bills for truckers and trucking companies in Idaho. Updated 2026-10-24.

Must-know rules · Weight, oversize & chains · Fees · Bills

Must-know rules

Idaho dropped its split truck speed limit on July 1, 2026, so trucks over 26,000 lbs can run the same posted 80 mph as cars on certain rural interstates. Chain-ups apply only to commercial vehicles on three northern passes, and placarded-hazmat trucks of 10,000 lbs or more must stop at every open port of entry. I could not confirm the H0667 nondomiciled CDL repeal, idling limits, Idaho's weight-distance or fuel tax and IFTA/IRP specifics, or hazmat tunnel and routing restrictions, so those are l

Researched by our AI agent from the linked sources on 2026-10-22. Always confirm with the source.

• Must knowExtra-length / excess-weight permit (up to 129,000 lbs)

  Gross weight on designated routes may go up to 129,000 lbs under a permit. Routes above 105,500 lbs are shown on ITD's Designated Extra Length Excess Weight map, available online and at Ports of Entry. Combinations must keep at least 500 feet apart except when passing.

  ITD Special Permit Rules (IDAPA 39.03.01 working rewrite)
• Must knowPermits go void in hazardous conditions

  An oversize/overweight permit becomes invalid en route when ITD, Idaho State Police or other law enforcement gives public notice of a hazardous road condition. The driver must check route conditions before travel.

  ITD Special Permit Rules (IDAPA 39.03.01 working rewrite)

Weight limits, oversize permits and chain laws

Idaho allows 105,500 lb on non-interstate highways but caps interstates at 80,000 lb. It has no seasonal carry-chains rule. Chains are required only on three posted passes (Lookout, Fourth of July and Lolo) when ITD finds conditions unsafe. I could not retrieve ITD's own permit-conditions pages (escort and time-of-day rules) or a fine amount, so those items are flagged below.

Weight limits

80,000 lb gross, 20,000 lb single axle, 34,000 lb tandem
Statute sets the general maximum gross weight at 105,500 lb. On federal interstate and defense highways the cap is 80,000 lb unless a permit allows more. Reducible loads may run above 105,500 lb up to 129,000 lb on non-interstate highways under a §49-1004 permit. The vehicle must meet the weight formula and registration-fee requirements. ITD publishes the approved routes on a 'Designated Extra Len
Non-reducible (non-divisible) overweight or overweight/oversize loads get a single-trip permit for a $33 administrative fee plus a per-mile road-use fee. The per-mile rates are in ITD's overweight fee schedule, which I did not retrieve. The annual overweight/oversize permit is $128 plus quarterly mileage fees (fees per IDAPA 39.03.01, effective 7-1-24; I could not confirm the 2026 schedule). Reduc Source

Legal size without a permit

8 ft 6 in wide, 14 ft high, 53 ft semitrailer
Single-trip oversize permit: $30 from Idaho Transportation Department (ITD) overlegal permit office, Boise (P.O. Box 7129, Mon–Fri 8am–5pm), with permits also ordered through ITD's online portal per
Official rule text I retrieved covers only lighting. Over-width vehicles and loads that travel from 30 minutes after sunset to 30 minutes before sunrise, or when visibility is under 500 ft, must display marker lights. Convoys of permitted loads are capped at four oversize loads between escorts, with a 14 ft width limit on black-coded routes and 12 ft 6 in on red-coded routes (archived 2019 rule). Source

Chain law

Chains required when signs say so
There is no seasonal carry-chains requirement in the statute I retrieved. ITD may require chains on all covered commercial vehicles on I-90 over Lookout Pass and Fourth of July Pass and on State Highway 12 over Lolo Pass when it finds conditions unsafe. It must give advance notice, provide pull-outs and not post chain requirements on bare pavement. The minimum is one tire on each side of one drive Source

• Must knowBridge formula and axle groups

  Weight on any group of two or more consecutive axles must meet the formula W=500((LN/N-1)+12N+36), where L is the distance in feet between the extremes of the axle group and N is the number of axles. Two consecutive sets of tandems may each carry 34,000 lb if the first-to-last axle spread is 36 ft or more. The statute also caps single wheels at 10,000 lb.

  Idaho Code §49-1001 Allowable gross loads

Fees and DOT requirements

Idaho's CDL fees are the same for Class A and B, and the heaviest-truck registration fee depends on both weight and miles driven in the preceding year. I could not confirm from an official source whether in-state-only for-hire carriers need separate state operating authority; sources conflict. I also found no source on state truck emissions programs.

Class B CDL

$60 for 8 years (about $7.50 a year)
ITD lists the CDL at $15 for 1 year (age 20), $30 for 3 years (age 18-21), $40 for 4 years (age 21+) and $60 for 8 years (age 21+). Knowledge tests are $5 each. The skills test costs $10 at the county plus a separate examiner fee. The commercial learner's permit is $29 and valid for one year. The ex Source

Class A CDL

$60 for 8 years (about $7.50 a year)
Idaho publishes one fee table for Class A, B and C, so Class A costs the same as Class B: $60 for 8 years or $40 for 4 years (age 21+). Test, permit and skills-test fees are the same as for Class B. Per ITD, the $190 examiner cap and $5 knowledge tests apply to all classes. See https://itd.idaho.gov Source

Registration, 26,001 lb straight truck

$248.80 a year Source

How registration is figured

Idaho Code 49-434 has two schedules. One covers commercial vehicles of 60,000 lb or less and the other covers vehicles over 60,000 lb. Over 60,000 lb, the fee depends on declared maximum gross weight and miles driven in Idaho in the prior July-June year, using 35 weight tiers and 5 distance tiers.
(a) 26,001 lb straight truck: ITD's registration fact sheet lists $248.80 for 12 months for 26,001-30,000 lb in what appears to be the commercial-truck table (the same fact sheet also shows $116.68 in a separate, noncommercial-looking table). The extracted table headings were unclear, so confirm with ITD Motor Carrier Services. The statute adds a $25 fee on top of the schedule fees for vehicles of Source

Intrastate operating authority

Unclear. No official state source found naming an intrastate for-hire authority, certificate or permit.. unclear, depends on the type of operation; see source.
I could not verify from an official source whether in-state-only for-hire carriers need economic operating authority. ITD's intrastate registration application has a haul-for-hire operation type that requires proof of insurance (https://itd.idaho.gov/wp-content/uploads/2025/04/full_fee_application.pdf). J.J. Keller, a compliance publisher, says intrastate carriers hauling exempt commodities need n Source

State DOT requirements

• Must knowIntrastate USDOT / state DOT number

  Under Rule 19 of the Idaho Motor Carrier Rules, intrastate vehicles with a GVWR of 26,001 lb or more, combination weight ratings, more than 8 passengers, or placarded hazmat must obtain an Intrastate DOT number. FMCSA issues the numbers through an online application. The ISP page is several years old, so confirm the current thresholds with ISP.

  Department of Transportation - Idaho State Police Commercial Vehicle Safety

See all 7 DOT requirements with full access

Fees change; confirm with the linked state source. Compare all states.

New Idaho trucking bills

Enacted signed into law · Pending still moving through the legislature · Did not pass

• Enacted ID H0667: Amends existing law to eliminate the nondomiciled CDL program in Idaho. Reported Signed by Governor on March 26, 2026 Session Law Chapter 167 Effective: 07/01/2026 · 2026-03-30

Bill data from LegiScan (CC BY 4.0).