Iowa Truck Speed Limit
No split in Iowa. Trucks run the same 70 as cars on rural interstates, and 70 is interstate only (Iowa Code 321.285(5)). Off the interstate the ceiling is 65, and only on fully controlled-access divided multilane highways, so a two-lane primary is not 65. Every other road runs the default limit, which went from 55 to 60 on July 1, 2026 under Senate File 378. Iowa DOT is still swapping about 1,800 signs, and the posted number is the one that binds until it changes. There is no separate, lower truck limit to track.
How fast a truck can run in Iowa
No split in Iowa. Trucks run the same 70 as cars on rural interstates, and 70 is interstate only (Iowa Code 321.285(5)). Off the interstate the ceiling is 65, and only on fully controlled-access divided multilane highways, so a two-lane primary is not 65. Every other road runs the default limit, which went from 55 to 60 on July 1, 2026 under Senate File 378. Iowa DOT is still swapping about 1,800 signs, and the posted number is the one that binds until it changes. There is no separate, lower truck limit to track.
Truck-specific rules and quirks
- Iowa posts 70 on rural interstates for all vehicles, with no truck split. 65 belongs only to fully controlled-access divided multilane highways plus the other divided multilane highways Iowa DOT designates, so a two-lane primary is not 65. Paved secondary roads run the default, which went from 55 to 60 on July 1, 2026 under Senate File 378. Gravel and other unsurfaced secondary roads stay at 55 by day and 50 at night (Iowa Code 321.285(4)).
What a speeding ticket costs
Speeding is a graduated scheduled fine. Fines double in a road-work zone.
Iowa Truck Speed Limit FAQ
What is the truck speed limit in Iowa?
Do trucks have a lower speed limit than cars in Iowa?
What is the speeding penalty for a truck in Iowa?
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 Traffic laws change and this can be out of date, so always confirm the current statute and obey posted signs before you rely on it.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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