Idaho Truck Lane Restrictions
Idaho has no truck-specific left-lane law. The rule that touches you is the general keep-right (Idaho Code 49-630). If you're rolling slower than traffic, stay in the right lane and use the left only to pass or turn left. It's a traffic infraction, so expect a fixed fine plus court costs. Run the left lane only when you're actually overtaking.
Some figures on this page are flagged medium confidence. The general rule is solid, but a specific corridor or fine should be confirmed with the state DOT before you rely on it.
Which lanes a truck can use in Idaho
Idaho has no truck-specific left-lane law. The rule that touches you is the general keep-right (Idaho Code 49-630). If you're rolling slower than traffic, stay in the right lane and use the left only to pass or turn left. It's a traffic infraction, so expect a fixed fine plus court costs. Run the left lane only when you're actually overtaking.
Roads, exceptions, and signs
- Where it applies: Statewide, all highways. Applies to every vehicle, not to trucks specifically.
- General rule: Idaho Code 49-630 — slower-than-traffic vehicles keep right; no crossing left of center on four-lane two-way roads except as marked.
- Ground-truth overview agrees: no truck-only left-lane ban exists in Idaho.
What a lane violation costs
Failure to keep right is a traffic infraction. A fixed penalty plus court costs (on the order of $90 total). No license points for the infraction itself. Exact schedule amount not separately confirmed.
Idaho Truck Lane FAQ
Can a truck drive in the left lane in Idaho?
Is there a truck lane restriction in Idaho?
What is the fine for a lane violation 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 Traffic laws change and this can be out of date, so always confirm the current statute and obey posted signs before you rely on it.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://legislature.idaho.gov/statutesrules/idstat/title49/t49ch6/sect49-630/. See our Terms & Disclaimer.
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