It’s a day we knew was coming after the sale of Convention Place Station for the Convention Center expansion, and now we have an official date: Buses will stop running through Convention Place Station on July 21.

In this phase of the plan, only the seven bus routes that use the station are affected: Metro routes 41, 74, 101, 102, 150, and 255, plus Sound Transit Express route 550. Those buses will travel on a temporary ramp between Ninth Avenue and the bus tunnel, which allows the rest of the bus tunnel to stay open—for now. Passengers will wait for the affected bus routes on Ninth Avenue, which will be a two-way street.

Other buses will continue running through the rest of downtown’s bus tunnels until March 2019, when the Washington State Convention Center officially owns the Convention Station property. At that point, they’ll all emerge to Third Avenue to mingle with an existing crowded bus corridor and car traffic, leaving only light rail in the bus tunnel.

City planners are examining some mitigations—including all-door boarding on Third Avenue—but with lots of moving parts, some long-awaited projects are being left behind, like connecting some of downtown’s bike lanes.

All this is just one element of what transportation planners are calling the “period of maximum constraint” for Seattle traffic, where multiple road and construction projects are expected to converge into heavy bottlenecks on downtown streets.

One silver lining: Metro expects the tunnel going rail-only will improve light rail capacity and service, especially with extensions underway to the north and east.

King County finalized an agreement to sell Convention Place Station in June of 2017 for $275 million in principal and interest over 32 years, with the money going to support both Metro operations and capital projects. In exchange, Pine Street Group, the developer behind the Convention Center expansion, will build on the soon-to-be-former station property.

The expansion has a tentative opening date of 2021—making it one of the construction projects contributing to an intense downtown traffic situation—but it comes with other public benefits, like bike lanes, affordable housing contributions, and funding a feasibility study on lidding Interstate 5.

This story has been updated to clarify that the buses will still run through the tunnel, but won’t pick up passengers at the station.