A long-term plan for toll lanes on I-405 has been sent to state lawmakers.

The I-405/SR 167 Corridor Funding and Phasing Report was submitted by the state Department of Transportation to the Legislature and the governor on Friday, Jan. 17.

The report outlines a two-phase approach for creating a toll-lane system from Lynnwood to Renton on I-405, connecting to existing toll lanes on Highway 167 in south King County.

The state is spending $334 million to convert existing carpool lanes into toll lanes, or “HOT” lanes, on I-405 from Lynnwood to Bellevue. Work on paving, striping and barriers for the project has begun. The lanes are expected to be ready for use as toll lanes in 2015.

The report recommends allowing two-person carpools to ride for free during off-peak hours and carpools of three or more people to ride for free at all times. Otherwise, drivers using the carpool lane would be charged an electronic toll.

Rates have not been set. They will depend partly on how far a driver will travel. The toll will automatically increase and decrease based on how many people are using the lanes.

The toll automatically increases when traffic in the express toll lanes is heavier and decreases when traffic is lighter.

As drivers approach the entry point to the express toll lanes, they will see a sign listing up to three destinations. The toll for each destination at the time is the price of that trip.

The lanes would be divided into three areas — Lynnwood-Bellevue, Bellevue-Renton and Renton-Pacific. One study assumed a minimum toll of 50 cents per area to start, increasing to 75 cents in 2018.

Buses and registered vanpools will travel toll-free in the lanes.

The second phase would require a new lane to be built from Bellevue to Renton and ramps constructed to connect the lane to existing carpool-toll lanes on Highway 167. That project, expected to cost more than $1.1 billion, has not been funded.

The new report recommends using $960 million from the gas tax and collecting the remaining $215 million through tolls to cover the cost. The report is unclear on whether an increase in the per-gallon gas tax would be required to raise the money. The earliest this phase could open is 2020, according to the report.

The report was developed by the state with input from an advisory group of elected officials representing communities along the I-405-Highway 167 corridor. The state held four meetings with this advisory group last year.

Bill Sheets is a writer for The Daily Herald in Everett, which is among the Washington state newspapers in the Sound Publishing group.