There are a lot of bus routes that go to Downtown. However, since Downtown is so overcrowded, many Downtown routes get major delays. I think Metro should move some routes of Downtown. People have mentioned the future Link and RapidRide systems, but here I only talk about what Metro can do at this moment to reduce Downtown congestion. I will talk about some specific routes in this post.
Instead of traveling south to Downtown, SR-520 routes will run north to University of Washington, serving the station at Husky Stadium. These routes can layover elsewhere on the UW Campus. Maybe a couple peak-only routes can continue serving Downtown, but there should only be 1 or 2 of them.
Routes 21 and 125
West Seattle already has the RapidRide C Line and Route 120 providing frequent connections to Downtown. Routes 21 and 125 will be modified to serve Alaska Junction instead of Downtown.
Routes 7, 48, and 106
There is a plan for Route 48 to take over Route 7 between Mt Baker TC and Rainier Beach. I think Metro should proceed with this plan. Trolley wire for Route 48 is currently being placed, so the combined route will still be able to operate using trolleybuses. Route 106 will be moved off of Jackson and onto Boren and Fairview to serve First Hill and South Lake Union.