It has four stops, including two that connect to Link light rail stations, and functions as an extension of the Downtown Seattle Transit Tunnel, which was formerly used by buses.

The entrance is located about two blocks away from ramps to Interstate 5, which most routes utilize to travel between Downtown Seattle and their southern terminal.

The busway was built by the Washington State Department of Transportation in the late 1980s at total cost of $4.5 million, as part of a package of improvements to Interstate 90, that also included the addition of significant bus transit infrastructure on the freeway.

The busway also has electronic sensors buried in the roadway, triggering transit signal priority as buses approach intersections.

[5][6] In November 2003, Sound Transit began construction of the Central Link light rail line, which included relocating utilities along the busway.

In heavy traffic, this maneuver slows buses, often negating the time savings achieved by using the SODO Busway.

As part of the 2007 Roads & Transit package, the Regional Transportation Investment District proposed building a direct connection from the Interstate 5 high-occupancy vehicle lanes to the SODO Busway at a cost of $83 million (2006 dollars).

The project also received contributions from SoDo businesses, including $5,000 from Starbucks, which has its corporate headquarters nearby,[14] and in-kind donations of paint from Sears, Home Depot and the city of Seattle.