The highway heads southeastward as a four-lane expressway, paralleling the routing of nearby Interstate 90 (I-90) to New York State Thruway exit 24.

This portion of Washington Avenue Extension is flanked on both sides by named Frontage Roads, both of which begin at NY 155.

At the same time, construction began on a new divided highway routing for Washington Avenue between Fuller Road and NY 155 along the southern edge of I-90.

[5][6][7] The highway, named Washington Avenue Extension, was completed by 1973[2] and designated as NY 910D, an unsigned reference route.

[8] As of May 2012, major reconstruction work is well underway to realign Washington Avenue Extension to the north of the CSNE UAlbany Nanotech College complex at its intersection with Fuller Road and build a roundabout interchange.