WSDOT finally widening northbound I-5 through downtown Seattle From Yesler Bridge over I-5 looking northward. (Photo courtesy of SDOT/Flickr) The state is finally addressing one of the biggest chokepoints in our region by widening northbound I-5 through downtown Seattle, but it will come with a cost for people who drive on I-90 and use the downtown collector-distributor lanes. The morning I-5 drive into Seattle is one of the worst congestion spots in the state. It routinely backs up about four miles, from before the West Seattle Bridge to the middle of the convention center. There are a variety of reasons for the backup, including that it’s a very popular stretch of freeway. There is also a lot of lane changing and weaving to access the downtown exits, the collector-distributor lanes, I-90, and the Express Lanes.