Trucking Regulations in Idaho
Complete guide to weight limits, speed limits, permits, chain laws, and special rules for commercial truck drivers operating in Idaho.
Max Gross Weight
105,500 lbs on designated state routes with permit
Truck Speed Limit
70 mph on rural interstates
Diesel Tax
$0.32 per gallon diesel + federal
Weight & Size Limits in Idaho
| Measurement | Limit |
|---|---|
| Max Gross Vehicle Weight | 105,500 lbs on designated state routes with permit |
| Max Axle Weight | 20,000 lbs single axle, 34,000 lbs tandem |
| Max Trailer Length | 75 ft overall combination on designated routes |
| Max Width | 102 inches |
| Max Height | 14 ft |
Speed Limits for Trucks in Idaho
Rural Interstate
80 mph (cars), 70 mph trucks
Urban Interstate
65 mph
Truck-Specific
70 mph on rural interstates
Fuel Tax & Tolls in Idaho
Diesel Fuel Tax
$0.32 per gallon diesel + federal
Toll Roads & Bridges
No toll roads in the state.
Chain Laws & Weather Requirements
Chains required on drive axles from October 1 to April 30 on designated mountain passes. ITD can mandate chain-up during storms.
Oversize & Overweight Permits
Idaho Transportation Department (ITD). Permits available online. Idaho has generous allowances for agricultural equipment movements.
Port of Entry & Weigh Stations
Ports of entry on I-15, I-84, I-90, and US-93. All commercial vehicles must stop. PrePass accepted.
Special Rules for Idaho
Hazmat Route Restrictions
Hazmat restricted through Coeur d'Alene city limits and in designated mountain pass areas. Designated routes for hazmat through Boise metro area.
Rest Area & Parking Rules
Rest areas allow 10-hour parking. Good truck parking availability outside Boise. No state anti-idling law.
DOT Inspection Frequency
Moderate. Idaho State Police commercial vehicle unit conducts inspections at ports of entry and roving enforcement on I-84 and I-15.
Looking for Trucking Jobs in Idaho?
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Frequently Asked Questions About Idaho Trucking Regulations
What is the maximum weight allowed in Idaho?
Idaho allows up to 105,500 lbs gross vehicle weight on designated state routes with a permit, significantly above the 80,000 lbs federal interstate limit. This makes Idaho one of the more generous states for heavy haul operations, particularly for agricultural and natural resource loads.
What is the truck speed limit in Idaho?
Idaho has a 70 mph truck speed limit on rural interstates while passenger vehicles can travel 80 mph. Urban interstates are 65 mph. This 10 mph differential is one of the largest car-truck speed differentials in the country.
Are chains required in Idaho?
Idaho requires chains on drive axles from October 1 through April 30 on designated mountain passes including Lookout Pass (I-90), 4th of July Pass (I-90), and various passes on US-95 and US-93. ITD can require chains at any time during winter storms.
How does Idaho handle oversize permits?
ITD issues oversize/overweight permits through their online portal. Idaho is relatively permitting-friendly, especially for agricultural equipment. The state's generous weight limits on state routes make it attractive for heavy haul carriers.
What are the port of entry requirements in Idaho?
All commercial vehicles must stop at Idaho ports of entry on I-15, I-84, I-90, and US-93 unless they have PrePass clearance. Ports check weight, credentials, fuel tax compliance, and safety. The Huetter port on I-90 is one of the busiest.