House lawmakers in Washington state passed a bill that would allow the state Transportation Department to open up state Route 167 high-occupancy vehicle lanes to drivers willing to pay a toll.

The House passed the measure 57-41 Feb. 16. It has been forwarded to the Senate.

HB2808 would authorize a pilot project to allow solo drivers to use 167 northbound and southbound HOV lanes between Renton and Auburn. The toll amount would depend on congestion levels.

Current HOV users would continue to have free access to the lanes.

The 167 project would be the first for the state. Similar HOT (high-occupancy toll) lanes already are operating in San Diego and Houston, with several other cities and states studying similar proposals.

The “HOT-lane” program would move an additional 12 percent to 13 percent of vehicles through the corridor at peak hours, the Seattle Post-Intelligencer reported. An estimated 400 vehicles an hour would move from the general purpose lanes into the underused car pool lanes.

The bill requires WSDOT to monitor the project and modify it if such problems emerge. It says the conversion of single HOV lanes to HOT lanes “must be taken as the exception for this pilot project.”

In addition, a “reasonable proportion” of toll revenue must also be used to increase transit, car-pool and van-pool service in the 167 corridor.