Almost, But Not Yet, on US 101

US 101 through-traffic sign even though it's still Interstate 80 at Fifth Street in San Francisco

The center panel on this sign assembly on westbound Interstate 80 at Fifth Street in San Francisco is marked for US 101, not for Interstate 80. That's because the Interstate 80 designation ends at the Central Skyway. The main freeway route continues southward as US 101.

By the way, notice all the billboards. This is one of the highest-traffic locations in the Bay Area, and a prime spot for billboard advertising.