State to wait and see on I-405 toll lanes at difficult merge (updated)

(Updated since original post on Thursday, Oct. 8.)

Two weeks into tolling, Snohomish County commuters continued to report spikes in congestion and trouble accessing the express lanes in the northern end, including a troublesome merge to and from Highway 522.

“This is not a complaint about the toll so much as the planning,” said Kevin Crowe of Everett, who commutes I-405 for his Boeing job and also to take his son to school in Woodinville.

To get onto Highway 522 in the mornings, Crowe must exit the toll lanes well before that, just past Highway 527. “Which throws me into the meat of the traffic for a several-mile crawl,” he said. “I am paying anywhere from 3 to 5 dollars to just be shoved into the worst congestion of the trip.”

Lyle Rice of Mukilteo, who commutes to Redmond for his job at Microsoft, also cited a lack of entry and exit points from the toll lanes at the north end as adding to traffic problems rather than helping alleviate them. An entry point at the top of a hill further complicates movement, he said.

“It really seems like it was designed off a 2-D flow map and not by somebody who lives in the area and actually drives it,” Rice said.

WSDOT Assistant Secretary for Tolling Craig Stone said the express toll lanes are still in a ramping-up period, and that crews have left room to make changes if needed.

Additional striping already went down near NE 160th Street to better mark express lane and general purpose lane traffic.

Drivers are getting used to the new lanes, and collisions can quickly slow traffic even further. October also is a heavy traffic month, with the University of Washington Bothell and other schools starting classes. “The whole system is very fragile,” he said. The express lanes work best for those traveling the full 17-mile length, he acknowledged.

Long-term plans call for adding a direct access ramp from Highway 522 onto the express toll lanes. But there’s no funding for the addition.

In the meantime, a new braided ramp in Bothell that separates drivers from NE 160th Street heading for Highway 522 aims to alleviate some of the traffic volumes coming onto I-405 south. Before, drivers heading to Highway 522 from NE 160th often took I-405 south for a short distance first.

New rules that allow transit to drive on the shoulders near the interchange during congested commutes also aim to help.

In general, when designing the access points, WSDOT looked at several factors, including symmetry between the northbound and southbound directions, providing enough room to merge, and minimizing conflicting weaving volumes.

It’s expected to take six months to a year to settle into a new normal.

“People are changing their patterns, and every individual is making a logical decision about how they want to travel,” Stone said.

Information from local cities about the impacts on side streets also will help provide a fuller picture. That data is expected in about a month.

It’s premature to say if local side streets in Bothell are seeing more traffic, said Jamal Mahmoud, transportation engineer for the city. “But in general, just based on my traffic observations, I do not see a huge impact,” he said.

But drivers like Crowe, the Everett dad, said side streets are definitely an issue. And tardy arrivals have spiked at his son’s school since tolling began.

“Six months to a year of late school and work arrivals is an absurd expectation,” Crowe added.

In the meantime, Michael Mates of Monroe proposes an “I-405 Misery Index.”

“The formula could be a measure of difficulty in getting from 405 on-ramp ‘x’ to closest HOV entrance ‘y,’” he said. The shorter the distance, the greater the difficulty.

Factor in the number of lanes to be crossed, the average difference between speeds in the general purpose and express toll lanes, and you’ve got a better picture than a not-to-scale WSDOT map, he said.

“Thus, if you have only half a mile to cross two lanes from the on-ramp, and you are going 20 mph while the HOV lanes are going 60, you are probably going to get into a wreck, or not make it,” Mates added.

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