A bill to authorize express toll lanes on Interstate 405 died in the state legislature last week after the Senate failed to vote on the measure in time for a March 5 deadline.

The bill would have allowed the state to operate high-occupancy toll (HOT) lanes from Lynnwood to Bellevue.

Rep. Judy Clibborn, a Mercer Island lawmaker and chair of the House Transportation Committee, says the bill faltered because of misconceptions about how the program would work.

Some skeptics were concerned that the bill would double tax motorists, charging them once to build the lanes and again to drive on them. Others thought the measure would turn general-purpose lanes into express lanes.

“There was enough confusion to slow it down, and I didn’t have the time and energy to push it through,” Clibborn said. “We’ll get it done next year.”

The state has proposed tolling to help pay for the completion of highway expansions along the entire length of I-405 and SR-167 between Lynnwood and Puyallup, a tract known as the Eastside Corridor.

The state is considering a plan that includes one or two HOT lanes along with existing general-purpose lanes for the whole corridor. No general purpose lanes would be lost.

“It would be a boom for this region to have that kind of connectivity,” Clibborn said.

A state study indicates that the Eastside Corridor serves around 1.1 million trips per day, and will likely carry 1.5 million drivers by 2030.

The study also predicts that the region will add another 1 million people and 700,000 jobs within the same timeframe.

HOT lanes along the entire Eastside Corridor will improve traffic times for the system, according to the study.

The state is running out of gas tax money to complete its planned expansion of the Eastside Corridor, and is hoping to bond against future tolling revenue to pay for remaining projects.

Bonding against future tolling revenue would be an entirely new form of investment – one that some consider risky.

The failed tolling bill would have allowed drivers carrying one passenger to use HOT lanes without charge.

A previous version would have required at least two passengers, which Clibborn says will be needed to generate the needed tolling revenue.

“It’s harder to get support if you keep it at two, but it doesn’t do the job of paying the revenue if you do it at one,” she said.

HOT lanes are already in place along SR 167, where the state has been running an $18 million test project since May 2008.

Speeds in all lanes along that system have improved by up to 10 percent, even though traffic volumes have grown by four percent, according to the state Department of Transportation.

Tolls on SR-167 topped out at $9, the maximum allowed under the pilot program.

The project generated around $400,000 in operating revenue during its first year, which was not enough to cover its expenses. Planners say the program is not designed to make money in its inaugural year.