Southern Freeway
Length: 6 miles
Routing in SF: From CA 1/I-280 (Junipero Serra Freeway) at County Line to
King Street/5th Street.
Construction: 1958, reconstruction 1990-1995
Route Numbering: US 101 (1958-1964), CA 82 (1964-1968), I-280 (1968-)
The Southern Freeway was originally built to handle El Camino Real (then US 101, now CA 82) traffic to the Bayshore Freeway, relieving Alemany Boulevard, which is a major arterial in southern San Francisco. Later, when it was clear that the CA 1 freeway was stillborn in San Francisco, I-280 was rerouted on the Southern.
Even before the rerouting, the Southern Freeway was to have connected to Interstate 80 at the old 480 interchange near Fremont St. Although work continued from 1969 to 1990, the plan eventually was scrapped in favor of moving the ramps to 5th Street and King Street, which nows serves PacBell Park. The old 4th Street exit was replaced with a parking lot for the ballpark, which is directly in the old ROW of
In 1989, I-280 from US 101 to 4th street collapsed in the Loma Prieta Earthquake. CalTrans inefficiency kept the freeway inactive for five years, compared to a downtime of several months for Interstate 10 in Los Angeles.
One of the strangest interchanges ever, and unique to the Southern, is the Mariposa/25th Street exit, which is set up like a "stacked diamond", demonstrated here:
Sources: personal experience, kurumi.com, cahighways.org, 1967 Rand McNally atlas.
|
