Iowa Weigh Stations & Ag Inspection
Iowa's rule rides on the sign. When a scale is open, you stop for weighing and inspection when signs or a State Patrol officer send you in (Iowa Code 321.476). Skipping it is a simple misdemeanor (Iowa Code 321.482): a scheduled fine in the low hundreds plus surcharge and CDL/CSA fallout. Fixed scales line I-80 and I-35, with weigh-in-motion and portable crews between them. Drivewyze and PrePass both offer a green bypass.
A detail here is flagged medium confidence — confirm with the state agency before you rely on it.
When Iowa makes you pull in
Iowa's rule rides on the sign. When a scale is open, you stop for weighing and inspection when signs or a State Patrol officer send you in (Iowa Code 321.476). Skipping it is a simple misdemeanor (Iowa Code 321.482): a scheduled fine in the low hundreds plus surcharge and CDL/CSA fallout. Fixed scales line I-80 and I-35, with weigh-in-motion and portable crews between them. Drivewyze and PrePass both offer a green bypass.
Stations, bypass, and inspection
- Who must stop: Only when a sign directs
- Where the stations are: Fixed scales sit on the main freight corridors (I-80 across the state, plus I-35 and I-29), with weigh-in-motion pre-screening and portable scales elsewhere. Stations post open or closed on signs and direct trucks to exit. A closed scale still leaves roving enforcement on the road.
- Bypass: Both operate in Iowa. Drivewyze PreClear and PrePass both cover Iowa weigh station sites, reading your transponder or app on approach. A green light bypasses an open scale; red or no signal means pull in. Neither clears an oversize or overweight load.
- Ag / border inspection: No agricultural or border produce inspection stations. Iowa handles weight and safety through the State Patrol's Commercial Motor Vehicle Unit (the former DOT Motor Vehicle Enforcement, merged into the State Patrol in 2023) and portable scales, not pest-quarantine checkpoints.
- Fine for passing an open station: Failing to stop and submit to weighing when directed is a simple misdemeanor (Iowa Code 321.476; penalty under 321.482): a scheduled fine in the low hundreds plus the state surcharge, with CDL points and CSA consequences. The exact scheduled amount is set by the citation.
Iowa Weigh Station FAQ
Do trucks have to stop at weigh stations in Iowa?
Can I bypass weigh stations in Iowa?
What is the fine for passing an open weigh station 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.legis.iowa.gov/docs/code/321.476.pdf. See our Terms & Disclaimer.
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