Microsoft officials announced that employees must return to the office three days per week, starting on March 2, 2026.
According to Geekwire, employees and their teams can determine for themselves which three days they would like to work in the office.
Given the already-strained transportation network in the Seattle region with the closure of two Northbound lanes on I-5, we wanted to examine how the recent announcement affects traffic on Eastside highways and bridges.
SR 520 East of I-405
Travel on SR 520 has been significantly impacted by Microsoft’s return to office policy. Speeds dropped across all days during the first week, with speeds on Tuesday, Wednesday, and Thursday showing the slowest travel speeds.
Speeds fell Eastbound during the PM commute period between 5% and 20% throughout the week, with the biggest drops on Monday and Wednesday.
Heading Westbound, travel speeds fell 16% on Tuesday to 47 mph, and fell 11% and 12% on Wednesday and Thursday, respectively.
I-405 Tuesday, March 3
Travel speeds fell heading into Bellevue during the morning commute. During the AM commute period speeds fell as much as 35% in between Tukwila and Bellevue and as much as 25% between Lynnwood and Bellevue. Thursday was the most impacted day during the 7:00-9:00 AM commute period.
During the evening commute, speeds dropped as much as 27% between Bellevue and Tukwila on Friday while speeds fell 21% Northbound between Bellevue and Lynnwood.
Early Conclusions
It is still early to fully assess the impact of the return-to-work policy by Microsoft. However, speeds on SR 520 and I-405 in both directions have already seen noticeable decreases during both commute periods. Unsurprisingly, Tuesday through Thursday saw the biggest impacts, though I-405 on Friday during the PM commute was an outlier.