Idaho law allows semi-trucks and passenger cars to drive the same 80 mph on interstates

Idaho ends split speed limits for cars, trucks

Truck drivers don’t just fight traffic – they fight speed limit rules that can make roads more dangerous. Out west, truckers already know the drill: different rules, slower speeds. In California, Idaho, Montana, Oregon and Washington, trucks are forced to run 5 to 15 mph slower than cars. Lawmakers have tried for years to close the gap. But critics often win the fight, arguing that letting trucks match car speeds would make roads less safe. The …

Idaho law allows semi-trucks and passenger cars to drive the same 80 mph on interstates

By: Joey Martin Originally Posted 3:51 PM, Mar 24, 2026 JEROME COUNTY, Idaho — A new law in Idaho will allow semi-trucks and passenger vehicles to travel at the same top speed of 80 mph on the state's interstates. Gov. Little signed House Bill 664 into law, and the measure will take effect on July 1. According to the bill, the difference in speed between vehicles is more dangerous than speed itself. Supporters argue that a 10 mph speed differenc…

New Idaho law equalizes speed limits for semi-trucks and cars on state freeways

A new Idaho law allows trucks to drive the same speed as cars on highways, aiming for smoother traffic flow.

Bill eliminating lower speed limits for semi trucks officially signed into law in Idaho

A law eliminating lower speed limits for semi trucks has officially been signed into law in Idaho this week.  House Bill 664 was signed into law by Governor Brad Little on Monday, March 23rd. The bill will eliminate the lower posted speed limits for commercial trucks and leave only one speed limit for all road-legal vehicles on Idaho roadways. The bill has been passed on the grounds that a 10 mph speed limit difference has been found to increase…