House approves bill making left lane a passing lane on multi‑lane highways

The Idaho House on March 17 approved Senate Bill 13‑40, a traffic‑safety measure that codifies the left lane as the passing lane on multilane highways and authorizes signage to encourage drivers to move right when safe.

Sponsor Representative (speaker 16) told colleagues that the bill’s intent is to improve traffic flow and reduce unsafe passing on the right: "When the right lane is vacant and available, you move to the right," the sponsor said, adding the proposal includes about $200,000 for signage. Supporters pointed to emergency‑response examples where blocked left lanes hindered first responders. Opponents said roadway conditions vary across Idaho’s 12,400 miles of highways and cautioned the rule may be less practical in some rural or mountainous corridors.

Lawmakers clarified that the bill would not remove discretion for local signage or DOT‑identified lane restrictions; enforcement would allow exceptions where the right lane is unsafe. After debate the House recorded that SB13‑40 passed the House and will be transmitted to the Senate for further action.

Next steps: the bill will move to the Senate; the sponsor said the measure is designed to be implemented through signage and existing enforcement procedures.