Idaho Trucking Regulations

Idaho is a critical freight corridor state connecting the Pacific Northwest to the Mountain West and beyond. I-84 runs east-west through southern Idaho, I-86 connects to I-15 at Pocatello, and I-90 crosses the northern panhandle — together forming the backbone of Idaho commercial trucking. The Idaho Transportation Department (ITD) manages permits, registration, and infrastructure, while the Idaho State Police Commercial Vehicle Safety Division handles roadside enforcement. Idaho is one of the few western states that permits Longer Combination Vehicles (LCVs), including triple trailers, on designated corridors including I-15, I-84, I-86, and I-90, giving carriers significant efficiency advantages on those routes. Agriculture drives a large share of freight: potatoes, dairy, wheat, barley, and sugar beets all generate substantial seasonal trucking volumes, and the state provides agricultural exemptions for certain intrastate operations. IFTA and IRP administration is handled through the Idaho Transportation Department. Carriers should be aware that mountain passes on I-84 and US-30 can impose seasonal chain requirements and road closures, and that oversize/overweight permits are required for loads exceeding the standard federal envelope.

Trucking authority and registration

  • Authority: Idaho Transportation Department — Division of Motor Vehicles
  • IRP jurisdiction: Yes (https://itd.idaho.gov/dmv/commercial-vehicle/)
  • IFTA jurisdiction: Yes (https://itd.idaho.gov/dmv/commercial-vehicle/)
  • DOT permit required: Yes — Idaho requires oversize/overweight permits issued by ITD for loads exceeding standard federal dimensions. LCV operations require special authorization and are limited to designated corridors.

Weight limits

GVWR80,000 lbs federal interstate standard
Single axle20,000 lbs
Tandem axle34,000 lbs

LCVs on designated corridors (I-15, I-84, I-86, I-90) may operate at higher gross weights under the federal LCV Freeze. Overweight permits are available through ITD for non-standard loads.

Notable regulations

  • Idaho allows Longer Combination Vehicles (LCVs), including triple-trailer combinations, on designated Interstate segments under federal LCV Freeze provisions.
  • Agricultural vehicles and implements of husbandry may qualify for intrastate exemptions from certain registration and permit requirements.
  • Chain control and road closure requirements apply on mountain passes seasonally; carriers must monitor ITD road conditions.
  • Oversize/overweight permits are available online through ITD's permit system; pilot car requirements apply to loads exceeding certain dimensions.
  • Idaho participates in both IFTA and IRP — carriers base-plated in Idaho file quarterly IFTA returns and obtain apportioned registration through ITD.

State trucking association: Idaho Trucking Association

Frequently asked questions

Are triple trailers allowed in Idaho?

Yes. Idaho permits Longer Combination Vehicles including triple-trailer combinations on designated Interstate corridors (I-15, I-84, I-86, I-90) under the federal LCV Freeze. Carriers must have proper authorization and operate only on approved routes.

What agricultural exemptions apply to Idaho trucking?

Idaho provides exemptions for certain agricultural vehicles and implements of husbandry operating intrastate. These exemptions can affect registration, permit, and hours-of-service requirements. Carriers should verify current exemption criteria with ITD, as they may vary by vehicle type and commodity.

How do I obtain an oversize or overweight permit in Idaho?

The Idaho Transportation Department issues oversize/overweight permits through its online permit portal. Single-trip and multi-trip permits are available. Loads exceeding certain dimensions require pilot cars and may require special routing approval.

Does Idaho have seasonal weight restrictions?

Idaho enforces seasonal weight and road restrictions in spring when frost thaw weakens roadbeds. Carriers should check ITD postings for active spring weight restriction zones, which typically apply to secondary state highways and county roads rather than Interstates.