OLYMPIA — The state’s march to toll a 40-mile stretch of highway between Bellevue and Puyallup has slowed as lawmakers struggle to agree on how those potential revenues may be used.

A bill giving the state Department of Transportation authority to construct express toll lanes on the south half of Interstate 405 and Highway 167 has yet to be voted on in either the House or Senate.

The hang-up is whether the agency should also be allowed to issue bonds that would be paid off with the future stream of toll receipts.

Supporters are pushing this as a way to immediately raise billions of dollars to carry out projects up and down the corridor, in some cases years earlier than now planned. Opponents don’t think the state should incur additional long-term debt in this manner, and want to protect use of tolls for day-to-day operations, maintenance and needed improvements in the areas where they are collected.

“There’s a lot of conversation going on about this right now,” said Sen. Hans Zeiger, R-Puyallup, a member of the Senate Transportation Committee. He is pushing to allow bonding as it could enable a major highway project in his district to be finished three years faster.

And Rep. Jake Fey, D-Tacoma, chairman of the House Transportation Committee, cautioned that “that there’s nothing guaranteed.”

Leaders of communities in Snohomish, King and Pierce counties are watching closely. If lawmakers fail to act this session, critical projects aimed at easing congestion won’t get off the drawing board as hoped.

One of those is a roughly $500 million undertaking to unclog a chokepoint on the north end of I-405 where express toll lanes have been in use since September 2015.

This plan would add a second toll lane between highways 522 and 527, a direct access ramp from Highway 522 onto the express toll lanes, and direct-access ramps at a rebuilt Highway 527 interchange. Those ramps are counted on being in place by 2024 when new bus rapid transit service comes online.

“The window is closing to get the work done,” said Davina Duerr, the deputy mayor of Bothell. “They will not be rapid if they are traveling in the general purpose lanes.”

Current law authorizes express toll lanes on a 15-mile stretch of Interstate 405 between Lynnwood and Bellevue. Revenues must be used to cover the costs of operating and maintaining the lanes. Anything above that must be funneled into improvements along the stretch. Right now, the law does not allow bonding of those dollars.

Those lanes generated $74.9 million in their first three years, far above expectations. A third went to operations and maintenance and roughly another third spent on projects and designing improvements to increase capacity north of Highway 522. There is $23.4 million available for other improvements to be determined by lawmakers at some point.

Lawmakers acted in 2015 to expand the use of toll lanes on all of 405 and on 167 up to Highway 512. They put two projects in the Connecting Washington transportation package which rely on an amount of money from tolling.

One will widen Interstate 405 to make room for two express toll lanes in each direction between Renton and Bellevue. It is a $1.23 billion project of which $215 million is supposed to come from tolls.

The other is known as the Puget Sound Gateway project. One of its key pieces is an extension of Highway 167 between Highway 512 in Puyallup west to I-5 in Fife. This is a $1.88 billion project of which $180 million is supposed to come from tolls. Right now, the prediction is it will all be done by 2031.

Zeiger said it is one of his goals to accelerate the Puget Sound Gateway.

On Tuesday, as the Senate Transportation Committee considered a bill to authorize tolling, he offered an amendment to allow the issuance of $1.5 billion in bonds, money that could be spent on that project.

Zeiger’s amendment to Senate Bill 5825 didn’t pass. The bill did advance and is awaiting action on the Senate floor.

Part of the political challenge is any bill that contains the issuance of bonds must garner votes of at least 60 percent of the members of the House and the Senate. It’s not clear there is a super majority of support yet, said Sen. Steve Hobbs, D-Lake Stevens, chairman of the Senate Transportation Committee.

Two Snohomish County lawmakers said they want to make sure tolls paid by Snohomish County commuters are spent on the north end of I-405 and not redirected to the south end or Highway 167.

Both said toll revenues collected on each highway should be kept in separate accounts to ensure the dollars are spent on those respective routes. The current Senate bill contains such a requirement.

“I tried to repeal the tolls twice, but the reality is they are here to stay,” said Sen. Guy Palumbo, D-Maltby. “The bill in the Senate that only authorizes new toll lanes south of Bellevue will do nothing for Snohomish County, and I oppose it in its current form.”

Rep. Jared Mead, D-Mill Creek, a member of the House Transportation Committee, said he is uncommitted on a particular direction.

Civic leaders have made clear the importance of acting this year to keep projects moving, Mead said. But, he said, Snohomish County commuters must be assured that the tolls they pay are spent on improvements on their route, not elsewhere.

“It’s a very sticky situation for me,” he said. “I know this is vital to our corridor. I don’t know if I will be able to get to a yes.”

Duerr, Bothell’s deputy mayor, said the city’s primary desire is for lawmakers to move forward and prevent further delay of projects necessary to help commuters all along the two highways.

“It’s one corridor,” she said. “We’re all in it together.”

Jerry Cornfield: 360-352-8623; jcornfield@herald net.com. Twitter: @dospueblos.