Idaho Truck Speed Limit
Idaho used to hold trucks to 70 mph where cars ran 80. That split ended July 1, 2026. Trucks now run the same posted limit as cars, up to 75 on most rural interstates and 80 on qualifying segments (Idaho Code 49-654). If your data still shows an Idaho truck limit below the car limit, it is out of date.
Some figures on this page are flagged medium confidence. The interstate limit and source are solid, but a specific corridor or penalty should be confirmed with the state DOT before you rely on it.
How fast a truck can run in Idaho
Idaho used to hold trucks to 70 mph where cars ran 80. That split ended July 1, 2026. Trucks now run the same posted limit as cars, up to 75 on most rural interstates and 80 on qualifying segments (Idaho Code 49-654). If your data still shows an Idaho truck limit below the car limit, it is out of date.
Truck-specific rules and quirks
- Idaho repealed its truck/car speed split effective July 1, 2026. Trucks may now run the full posted limit, up to 80 mph on qualifying interstate segments. Older apps and cheat-sheets still show Idaho as a split state — it is not anymore.
What a speeding ticket costs
Speeding is a graduated infraction set by the county. Work-zone fines double.
Idaho Truck Speed Limit FAQ
What is the truck speed limit in Idaho?
Do trucks have a lower speed limit than cars in Idaho?
What is the speeding penalty for a truck in Idaho?
Reference information for planning, not legal advice. Traffic laws change and this can be out of date, so always confirm the current statute and obey posted signs before you rely on it. Last reviewed July 2026. Source: https://www.iihs.org/topics/speed/speed-limit-laws. See our Terms & Disclaimer.
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