Congestion along Interstate 405 has improved in some places, and has gotten significantly worse in others, leaving Bothell in the lurch as commuters north of State Route 522 in both directions slog through heavier traffic.
An independent review of the state Department of Transportation’s (WSDOT) data, conducted by the University of Washington, on the effects of toll lanes along the I-405 corridor from Bellevue north to the Interstate 5 interchange reveal a mixed bag, Washington State Transportation Center UW Director Mark Hallenbeck said.
“In specifically the Bothell area, yes (congestion is worse),” Hallenbeck said, describing the effects of tolling in terms of ‘winners’ and ‘losers’. “But as those people head southbound, if those people are getting on at 522, and off at 85th, those people win.”
After tolling was implemented last fall by the WSDOT, data shows congestion shifted dramatically to the northern end of the corridor, particularly from the State Route 522 interchange up to I-5.
In the southern reaches of the corridor between Bellevue and Kirkland, what used to be a long slog of congestion in the northbound lanes has turned into intermittent patches of stop-and-go traffic mixed with free flowing stretches of highway.
However, north of SR 522 in both the northbound and southbound lanes, heavy congestion in the general purpose lanes greatly increased. This is attributed to the SR 522 and SR 527 interchanges, and a bottleneck due to a loss of lanes, as well as greater numbers of drivers on the road, Hallenbeck said.
“If you’re getting on at 527, you’re suffering the worst of it, but it’s not like 522 to 527 was ever a happy place to be” said Hallenbeck, but said congestion had increased. “That is a much uglier condition, no doubt about it.”
For southbound drivers, the situation is much the same, congestion has diminished heading south from Kirkland, but has increased from I-5 to SR 522, with noticeably more time spent in stop-and-go traffic.
Congestion in the carpool lanes has shifted north as well since they were converted to toll lanes.
“Their (WSDOT) real problem is very simple,” Hallenbeck said. “There’s way too many people trying to drive on the corridor.”
In response to heavy north-end congestion, the WSDOT is analyzing various strategies to improve traffic flow from what I-405 Project Director, Kim Henry, said.
“The increasing congestion we have up there is really a result of what’s going on within the region, and the corridor,” he said. “Between 2012 and 2014 we saw a 46 percent increase in the level of congestion that’s occurring up there.”
The corridor, Henry said, is essentially divided into two projects north and south of SR 522. The legislature only approved funding for additional lanes south of SR 522 in previous sessions.
The lower portions of I-405 have five lanes, which bottleneck into only three at the SR 522 interchange, one of which is now a toll lane.
Of particular concern, Henry said, was the SR 527 interchange, both northbound and southbound, where drivers enter the highway and are forced to ‘weave’ across lanes to get into or out of the toll lanes, jamming up traffic.
Henry said the WSDOT will be looking at implementing various changes, including adding more lanes, constructing an additional bridge for the SR 522 interchange or widening the existing one and allowing drivers to use the shoulder as an additional lane during peak hours between SR 527 and I-5.
On Jan. 28, the state legislature’s House Transportation Committee met to discuss the effects of toll lanes on I-405. House Democrats issued a press release this week, authorizing the WSDOT to lengthen access to toll lanes in problem areas to make access safer and easier.
A proposed state Senate, approved by the Committee of Transportation, seeks to remove tolls in the lanes between 7 p.m. and 5 a.m. and on weekends and holidays.
The tolls have been unpopular since they were implemented, with one online petition by a group called Stop405Tolls reaching nearly 30,000 signatures.
One of the main grievances many residents have with the toll lanes is that only vehicles with three or more passengers can use them free of charge during peak hours. The lanes had previously been free carpool lanes accessible for vehicles with more than two or more occupants.
However, Hallenbeck said this change was necessary for future transportation improvements, specifically rapid bus transit which could be included in the Sound Transit 3 expansion.
“If you don’t do that, things actually get worse,” he said.
Before tolling began, busses were often stuck in the carpool lanes which were crammed with two-person vehicles, causing inconsistent travel times, Hallenbeck said. Forcing two-person carpools to pay reduces the number of overall cars in the toll lanes, and creates more reliable movement for buses and three-or-more person cars, increasing the overall capacity of the corridor.
“If you want people to be on the bus, they actually have to gain something from losing the ability to leave whenever they want,” he said. “To make that happen, you have to make the buses an attractive place to be, and you have to make it possible for people to get to them.”
Hallenbeck said before the toll lanes, I-405 wasn’t working for either personal vehicle or transit commuters, but now it is working better for buses and three-person carpools for a net gain in mobility and shorter commute times for the length of the corridor.
Ideally, he said, expanding the highway would be the best option for the WSDOT, but one for which funding has not yet materialized from the legislature.
“Their (WSDOT) job is not to make your life bad, their job is to try and fix it,” Hallenbeck said. “Their problem is they only have so much money. Some of the things they tried didn’t work, but they’re trying to fix them.”
Henry said readjusting the toll lanes and exploring additional alternatives is all part of the process of creating a better I-405 corridor.
“Bad weather, short days and holidays all had a pretty big impact as people were still trying to figure out how this new system works and operates,” he said. “I firmly believe that things are going to smooth out over time.”
Congestion heatmaps provided by WSDOT/UW.