Higher tolls could improve I-405 travel times, WSDOT study says

Higher tolls could improve I-405 travel times, WSDOT study says
Although the dynamic tolling system on a 17-mile corridor of Interstate 405 is failing to one of the two requirements under state law, a new WSDOT study carried out by the University of Minnesota recommends numerous ways to improve travel times. Photo: WSDOT

The fate of dynamic tolling of 17-miles of high occupancy (HOV) lanes on Interstate 405 between Bellevue and Lynnwood could have long-term implications for Eastside traffic congestion reduction and management policy. The Washington State Department of Transportation (WSDOT) envisions tolled lanes running the entire 40-mile corridor down to State Route 167 in Renton.

But discontinuing the I-405 tolls could thwart that vision. Two years after its inception, the I-405 tolling is failing to meet one of the two requirements necessary to remain in operation under state law. The long and short of it is that while more vehicles are moving through the corridor than before and the HOV lanes have faster, more reliable times than they did prior to tolling, it’s still not meeting the mark set by the legislature.

Yet, a recent study of the corridor for the Joint Transportation Committee suggests that lawmakers may resort to higher maximum toll rates and other alterations in order to improve those metrics, rather than shut the system down. The results of the report were shared to panel members at a December 14 work session, where the discussion may set the tone for possible legislative action come January.

The corridor performance analysis study was authored by the University of Minnesota’s Department of Civil, Environmental, and Geo-Engineering and included a list of recommendations on how to improve the performance metrics that are failing to meet standards under state law.

Incidentally, the study’s scope did not include whether the system should be abolished and the corridor restored  to previous use of HOV lanes. In a recent memo, Washington Attorney General Bob Ferguson said the system only needs to meet one of the two state goals; reiterating the state law itself, the University of Minnesota study states that “if measures…above are not met within two years of ETL (express toll lanes) facility operation, statute directs the ETL project on I-405 be terminated as soon as practicable.”

The first objective is for I-405 toll payments to cover its operating expenses. On that, the system has met its goal many times over. Since opening in September 2015, the tolls have generated $45 million in revenue for WSDOT. Of that, less than half ($19 million) was needed to pay for operation costs.

However, the lanes – constructed using gas tax dollars – are still failing to maintain a 45 mile per hour (mph) average speed 90 percent of the time, the second objective mandated by state law. During the latest six-month period (January to July) the northbound lanes had an average speed above 45 mph 85 percent of the time, 78 percent for the southbound lanes.

Also, the general-purpose lanes experienced “no significant change” in trip times as the result of tolling.

However, during that time the corridor in both directions experienced an 11-percent increase in vehicle volume, albeit an additional HOV lane opened for tolling added an additional 10 percent road capacity. WSDOT also invested $11 million into a 1.8-mile northbound shoulder lane.

One of the ways the study’s authors recommend fixing the HOV travel times is by raising the maximum toll rate above its current $10 limit, which is reached 15 percent of the time. That limit was created by the Washington State Transportation Commission shortly before tolling began.

Other recommendations in the study include:

  • Extending the peak period times from 5-9 a.m. by one hour to 10 a.m.;
  • Charging separate segment toll rates based on the traffic conditions; and
  • Making it easier for vehicles to transition in and out of the tolled lanes.

Matt Schmit is a project manager for the University of Minnesota’s Humphrey School of Public Policy. He told lawmakers at the December 14 work session that “during that 17-mile stretch of the corridor, conditions can change drastically. The price that a car locked in at that one time may not be reflective of conditions downstream or upstream so to speak.”

“When traffic builds on the I-405 corridor, it quickly builds,” he added. “You really don’t want to hit the maximum toll rate; it’s a tool that’s only useful if you’re not hitting that maximum toll rate.”

Dr. Alireza Khani of the University of Minnesota added that: “we don’t want to surprise drivers so when they see a rate, they enter and at the end they pay something differently; they would be able to lock in a price. We don’t want to change the price for the vehicles that are already in the lanes. Drivers would be able to lock in a price and pay that one.”

House Transportation Committee Chair Judy Clibborn (D-42) seemed open to the idea of higher tolls, telling colleagues “I would like to just put in everybody’s mind that…we’re not really tolling for the money. We’re tolling for the management. We’re talking about raising tolls, but we’re really trying to manage throughput. I just want to make sure everybody understood that.”

However, panel member such Sen. Dean Takko (D-19) voiced concerns that varying toll rates would negatively affect traffic. “If I understand what you’re saying, you’d get into one segment and it says $3. You get into the next segment, it says $8. Doesn’t that create a problem if it’s that congested that the prices are getting high enough that you want to peel off?”

Schmit replied that “this is the challenge that you have. The peak of the peak periods, where the traffic is at its worst.”

Takko’s apprehension is shared by Mariya Frost, director of the WPC Coles Center for Transportation. In a blog post, she wrote that variable tolls for each segment “would be like ordering a steak at a restaurant for $30, and about 1/3 into your meal, being told it’s now $100. People would have maybe a minute to do math and make split financial decisions while driving.” That could mean bottlenecks where two segments meet, she adds.

Frost also criticizes the recommendation to extend the peak period time to 10 a.m., rather than transitioning it to start an hour later at 6 a.m. The study itself concluded that “the actual peak travel time starts after 6AM and extends beyond 9AM.”

“They have one hour to toll and one more hour of free flow speeds that could pad their metrics,” she said. “It’s horribly dishonest.”

However, a variety of factors may discourage legislators from letting the toll system go defunct. In addition to improving HOV lane travel times despite an influx of new drivers in all lanes, the Everett Herald reports that restriping the lanes and removing the tolling equipment could cost $13 million. Also, Sound Transit CEO Peter Rogoff at an October meeting said the agency may alter planned investments in that corridor, such as bus rapid transit, if the tolling is eliminated.


  1. It might also help if people had a few more transportation options, such as a half a dozen transportation companies, that they have today. Let’s open the market and see what it can do.


Please enter your comment!
Please enter your name here