7, I-5, Seattle Weekly hours of bottleneck congestion: 256 Worst bottleneck: Southbound, 45th St/Exit 169 Length of worst bottleneck: 1.46 mi Weekly hours of congestion on worst bottleneck: 34 Speed of worst bottleneck when congested: 21.3 mph

The expert opinion: “We have one major problem in downtown Seattle, and that is physical restraints,” says Paul Tosch, traffic reporter for KOMO 1000. “We only have so much room to put more freeway through downtown Seattle because we have water to one side and all the downtown buildings to the other. And I mean we don’t have room for one more lane.”