The only comfort from the busy first week of lane closures on northbound I-5 is that it began as bad as it possibly could.
“On Monday, it appeared that everyone pulled the same lever. In other words, everyone left early, and when everyone does exactly the same thing, we don’t achieve the variety we would prefer.” RB McKeon, a Public Information Officer with the Washington Department of Transportation’s Northwest region.
McKeon mentioned that Tuesday morning saw improvement, with Wednesday being even more favorable. Nevertheless, speeds remain reduced and travel durations are extended, as noted by Bob Pishue, a transportation analyst from Inrix based in Washington. The impact of people steering clear of I-5 is evident in the data as well.
“Travel speeds have decreased considerably throughout the day on some of these major detour routes,” Pishue said.
Pishue notes that the data indicates Southbound commuters traveling from north of Seattle are facing the most difficulty, since the I-5 Express lane is currently only accessible for Northbound traffic to compensate for the closed Northbound lanes, which will remain shut until August 15th.
“It may begin as early as four or five in the morning,” Pishue said.
On I-5
Southbound traffic is 35% slower between 7 a.m. and 10 a.m., compared to last week. The congestion continues into the period from 11 a.m. to 2 p.m., with speeds decreasing by 32 percent. In the evening, southbound movement improves, but at that time, northbound traffic slows down by 29 percent relative to the previous week.
On SR 99
Data indicates this is one of the routes people are using most frequently to bypass I-5. Southbound traffic in the morning is moving 36 percent slower than last week and 32 percent slower at midday. In the evening, Northbound traffic is 29 percent slower.
15thAvenue NW
The westernmost main road (even though it’s not close to interstate levels) leading into Downtown Seattle is experiencing significant delays. Although midday traffic remains similar to last week, southbound traffic in the morning is 14 percent slower than last week, and four percent slower during the evening.
I-405
The only alternative interstate route involves circling the Metro area to reach Seattle from Lake Washington. Many drivers seem to be taking this approach, as southbound traffic experiences a 2 percent slowdown in the morning, 20 percent slower during midday, while northbound traffic becomes 19 percent slower in the evening.
25thand Montlake
Similar to 15th Street to the west, 25th Avenue NE serves as a primary road that wasn’t designed for highway-level traffic, yet it’s experiencing an increasing number of vehicles during I-5 lane closures. This street, located between Lake Washington and I-5, is facing heavier congestion from more drivers. Morning travel speeds are 17% slower, dropping to 19% slower during midday for southbound traffic, compared to last week. In the evening, northbound traffic is 14% slower.
Pishue notes that the peak traffic volume during rush hour is beginning an hour earlier, particularly on I-5. According to data, on Monday and Tuesday of this week, speeds began to decrease around 5 a.m. on I-5. By 6 a.m., speeds had already fallen below 40 miles per hour. Traffic congestion has started around 7 a.m., and southbound travel speeds do not return to regular levels until after 4 p.m., when northbound traffic begins to rise.
“You end up getting hit with two problems. The traffic is more intense, and it starts an hour sooner,” Pishue said.
In comparison, speeds on southbound SR 99 begin to improve around 11 a.m. Sound Transit notes an increase in passengers this week as the lane closures started. Parking lots and garages in northern communities had been consistently filling up since they opened in 2024. This week, they are reaching capacity an hour earlier, before 8 a.m., according to Sound Transit Public Information Officer David Jackson.
“If you’re hoping to grab a parking space, you’ll need to be the first one there to secure it,” Jackson said.
“People might want to consider using public transportation to reach other forms of transit,” Jackson proposed.
There are methods to organize your transit journey through King and Snohomish Counties:
Sound Transit
King County trip planning
Community Transit
McKeon recognizes that not everyone has a flexible timetable and offers the option to adjust shifts, but she encourages those who can to travel during times outside of the busiest periods.
“If you possess that flexibility, please think about how you can support the system. We truly believe that we’re all in this together and we’ll get through it as one,” McKeon stated.
