OLYMPIA — A new report released Wednesday suggests traffic could move at faster speeds in the I-405 toll lanes if the state charged higher rates in the most congested periods of the daily commutes.
It recommends lifting the cap on the maximum toll, which now sits at $10, and charging by segment instead of letting drivers lock in a single toll rate for the entire 17-mile corridor between Lynnwood and Bellevue.
And it says the state should fix the math used to set rates so higher tolls are charged sooner to more closely match actual traffic conditions.
The study was produced by the Department of Civil, Environmental and Geo-Engineering at the University of Minnesota. The draft will be presented to the Joint Transportation Committee of House and Senate lawmakers Thursday morning with the final version due to the Legislature in January.
At that time, state lawmakers said the future of the lanes hinged on achieving two benchmarks. The lanes needed to generate sufficient revenue to pay for their operation and traffic needed to move at least 45 miles per hour at least 90 percent of the time.
In this new report, the Minnesota consultants analyzed a dossier of data compiled by the state Department of Transportation on speed, travel time, volume and toll rates from the opening of the lanes through June 2017.
Toll lanes are paying for themselves but traffic was moving above 45 mph only 85 percent of the time in the northbound lanes, and 82 percent in the southbound lanes, in the first six months of this year. While toll lane users shaved a few minutes from their commutes, that cannot be said for those driving in the general purpose lanes, which have experienced little change since the toll lanes opened.
The consultants cite two explanations for the toll lanes inability to meet the benchmarks.
Overall, there are more cars on the road. Traffic volumes are up nearly 11 percent since they opened. With volumes expected to continue growing it will be hard to meet the benchmarks unless capacity — as in more lanes — is added, they note.
A second problem, they said, is the algorithm used for pricing is “not adequately responsive to rapidly increasing traffic volume during peak periods.”
The consultants found the $10 maximum toll rate was reached on average 15 percent of the time in the peak period between January and June 2017. The percentage was higher in the southbound direction than in the northbound direction, they found.
Hitting the maximum indicates the express lanes are in “breakdown” mode, the authors wrote. “For dynamically-priced toll facilities such as the I-405 ETL,(express toll lanes) the goal is to reach the maximum toll rate only rarely.”
Changing the algorithm used for calibrating rates takes aim at a different issue. The study found drivers can pay a rate when they enter the lanes that is as much as $4 lower than the rate at the time they exit the lanes. The state currently updates its rates every five minutes but is looking at reducing the time to three minutes.
Other short-term tinkering suggested includes expanding peak morning commute hours to 10 a.m. and doing away with double white lines to open up access in some parts of the corridor.
Long-term recommendations with higher costs attached are already on the state’s wish list, including expanding the highway north of Highway 522 and extending a second express toll lane up to I-5 in Lynnwood. Those are all projects it foresees using toll revenue to help accomplish.
The consultant’s report also calls for more transit options. Sound Transit expects to add bus rapid transit routes on I-405 around 2024 as part of the ST3 package.
Rep. Mark Harmsworth, R-Mill Creek, a member of the transportation committee, said the consultants “call out clearly” that the lanes are failing to meet the benchmarks. But he’s disappointed in their suggested solutions.
“The recommendations — increasing the tolls to get people out of the lanes — is not acceptable but is what the DOT (Department of Transportation) is likely to do to try to improve the throughput,” he said. “This report was about making the toll lanes succeed rather than fixing the general purpose lanes.”
Sen. Steve Hobbs, D-Lake Stevens, chairman of the Senate Transportation Committee, said it’s good there’s revenue that can be used to make improvements. But he said he’s opposed to lifting the cap on rates.
“I don’t think you’d want to do some of those recommendations because the public wouldn’t support them,” he said.
Patty Rubstello, assistant secretary of transportation for urban mobility and access, said she was pleased with the analysis as it validated the data they have collected and been sharing with the public and lawmakers.
She said recommendations for boosting the maximum rate or charging by segment are subjects that would require much more investigation and conversation.
They are focused on getting improvements on the north end and opening toll lanes on the entire length of I-405. Design is already under way to widen and extend express toll lanes down to Renton, with construction expected around 2020.
Planned north-end improvements include a new Highway 522 interchange, and adding a lane from Highway 522 to Highway 527. The state can commit to finish those projects and others by 2024 if lawmakers continue to allow tolling and also identify other sources of revenue, according to a DOT report presented to the state Transportation Commission on Tuesday.
If the state continues to allow tolling and use only toll revenue — for a “pay as you go” approach — the improvements would happen in stages and could be fully delivered by 2033.