Idaho Bill Seeks to Match Truck and Car Speeds

Idaho Bill Would Equalize Truck and Car Speeds on Freeways

A new bill in Idaho could change how fast trucks travel on highways by aligning speed limits for commercial vehicles with those of passenger cars. The proposal, known as House Bill 664, has advanced in the state legislature and is moving to the Senate floor for further consideration. The measure would remove the current difference in speed limits between trucks and cars on Idaho freeways.

What the Idaho Speed Limit Bill Would Change

Under current Idaho law, large trucks must travel at lower speeds than passenger vehicles on many highways. In some areas, trucks are limited to speeds about 10 miles per hour lower than cars.

House Bill 664 would change that rule. The bill proposes that vehicles with five or more axles and weighing over 26,000 pounds follow the same posted speed limits as other vehicles.

This would apply to interstate highways, state highways, and other roadways across the state.

Supporters Say Equal Speeds May Improve Traffic Flow

Supporters of the bill say that removing the speed difference could help improve traffic flow and reduce congestion.

Some lawmakers argue that differences in speed between trucks and cars can create unsafe driving conditions. They say that when vehicles travel at different speeds, it may lead to more lane changes, merging issues, and sudden braking.

As a result, aligning speeds could make traffic movement more consistent across highways.

Trucking Industry Raises Safety Concerns

At the same time, the proposal has raised concerns within parts of the trucking industry.

Some industry representatives say that higher speeds for heavy trucks may not improve safety. They point out that large commercial vehicles require longer stopping distances and may be more difficult to control at higher speeds.

Because of this, there are concerns that equal speed limits could increase risks in certain driving conditions, especially in high-traffic areas or during poor weather.

Load and Equipment Standards Remain Unchanged

The bill does not change how trucks are defined under Idaho law. It still applies to vehicles with five or more axles and a gross weight over 26,000 pounds.

Other regulations related to vehicle safety, weight limits, and CDL requirements would remain in place.

The proposal focuses only on speed limits and does not include changes to enforcement practices or driver qualifications.

What Happens Next with the Idaho Bill

House Bill 664 has advanced through committee and is now headed to the Idaho Senate floor for further debate and voting.

If approved by lawmakers and signed into law is set to take effect on July 1, 2026. The change would allow trucks to travel at the same posted speeds as passenger vehicles across Idaho highways.

State officials and industry groups are expected to continue discussions about how the change could affect safety and traffic conditions.