This morning, Metro sent out a press release discussing the proposed U-Link changes it released last night. Also in the press release was confirmation of another Link-related rumor that has been swirling for a while. In September 2015, Sound Transit will start testing Link trains on the U-Link alignment, which will increase the number of Link trains in the tunnel, especially during peak hours, when a train will arrive every six minutes.
To create space for these extra trains, six peak-hour bus routes serving North Seattle, Shoreline, Issaquah, and Sammamish are leaving the tunnel, effective September 26, 2015. Northbound, routes 76, 77, and 316 will use either Third or Fourth Avenue (Metro has yet to confirm which). Southbound, routes 216, 218, and 219 will pick up on Second Avenue.
To put it mildly, joint operations has not worked well during afternoon peak since Metro and ST began collecting fares on buses at tunnel stations. Perhaps there is hope that reducing the number of peak bus operations will make things a little bit smoother.