[1] The eastern terminus of OR 8 is an interchange with U.S. Route 26 (which is, at that point, the Sunset Highway) just west of the Portland city limits and the Washington-Multnomah county line.

[2] Continuing west, OR 8 enters the suburb of Beaverton, and after its interchange with Oregon Route 217, a freeway, its posted name changes to the Tualatin Valley (TV) Highway at Hocken Avenue.

TV Highway continues west as an expressway out of Beaverton, through the communities of unincorporated urban Washington County, including Aloha, where it runs right next to chipmaker Intel's facilities.

At Cornelius the road is again split into a one-way pair, with westbound traffic running on Adair Street, and eastbound on Baseline.

In downtown Forest Grove the road splits again, with eastbound traffic running on 19th Street, and westbound on Pacific Avenue.

[3] Constructed of cement, it partly replaced a county road built of dirt that ran on the southern side of the railroad tracks.