On Wednesday, September 16, two semi-trucks collided heading Southbound on Interstate 5 near the Ship Canal Bridge, leaving traffic snarled around the region for hours.
At about 5:30 AM, two semi-trucks collided just south of the Northwest 45th Street exit in Seattle, closing three lanes for about 2.5 hours. The crash immediately sent travel speeds plummeting on I-5 with ripple effects to other roadways across the region as travelers diverted to alternative routes.
Travel Speeds Nosedive During Morning Commute
Expectedly, travel speeds on I-5 heading Southbound from Everett dropped significantly soon after the crash. Normally, during those early morning hours, travel speeds are around 60 miles per hour, but in just 15 minutes after the collision, travel speeds fell to 25 mph, a 58% reduction. By 7:15 AM, travel speeds fell further to 16 mph, down 56% from normal. Above average congestion stretched throughout the day heading into the evening commute.
Average Speeds on Southbound I-5 vs Typical Wednesday
Other routes also experienced above-average traffic. Speeds heading Westbound on I-90 fell 61% below normal by 9:15 AM and stayed slower than normal through 10:30 AM.
Even I-405 drivers saw increased congestion, with travelers on I-405 Southbound into Bellevue averaging just 15 mph instead of the typical 25 mph.
Thankfully in the large I-5 crash, no major injuries reported. The incident reminds the public of the fragile road and transportation network in the Puget Sound Region, harkening back memories of the famed “fish truck accident” that left the region snarled in traffic.