State Route 260

As northbound California 61/260 leaves the city of Alameda (signed as California 61, but is legislatively California 260), it gains freeway characteristics as it passes under the off-ramp from southbound California 260 to Constitution Way.

07/05/04

Approaching the Posey Tube, which takes California 260/61 under the Oakland Inner Harbor Channel, use the left lane for downtown Oakland/Harrison Street and the right lane to Interstate 880 (Nimitz Freeway).

07/05/04

The Posey Tube was named for Alameda County Surveyor George Posey, who was involved in the original design and construction of the tube. Built well before the parallel Webster Tube, it was planned in stages between 1908 and 1923, with construction beginning in 1925 and concluding with the opening on October 27, 1928. The opening date on the sign is considered to be incorrect, as it was opened in 1928, not 1927. A plaque behind the 1927 sign reveals the correct date to be 1928.¹

07/05/04

The grand entrance to the Posey Tube is designed to act as a collar to prevent water from seeping into the tube. The tube carries two lanes of traffic one way toward Oakland. The other tube (Webster Tube) carries the southbound direction, and it was not constructed until 1968 due to increasing traffic needs. Both tubes were retrofitted for earthquake safety between 1999 and 2003.

07/05/04

View of the interior of northbound California 61/260/Posey Tube.

07/05/04

California 61/260 emerges from the tube, and a second sign advises travelers to Interstate 880 to prepare to make a right turn. Note the use of the button copy shield that was pasted over a California 17 shield, thus betraying the age of this sign.

07/05/04

After emerging from the Posey Tube, this end California 61 shield is placed, alongside a freeway sign pointing the way to Interstate 880 (Nimitz Freeway). Continue straight ahead on Harrison Street to enter downtown Oakland.

07/05/04

Heading east on 7th Street, the first ramp is for Interstate 880 north to San Francisco (with connections to Interstate 980, Interstate 80, and Interstate 580) via Jackson Street. Continuing straight ahead, 7th Street connects with I-880 south to San Jose and the South Bay.

07/05/04

Freeway entrance for Interstate 880 north and Interstate 980 east from westbound Jackson Street.

07/05/04

This sign for Broadway and north Interstate 880 is found on the on-ramp from Jackson Street.

07/05/04

The Webster Street (southbound) and Posey Street (northbound) Tubes, which together constitute California 260, were seismically retrofitted between 1999 and 2003. The Posey Tube was constructed in the 1920s and the Webster Tube was constructed in the early 1960s; both structures are unique to the area and hold a degree of historical value. Both tubes are 4,500 feet long (including approaches), and the Posey Tube was at one time the largest such tube in the world. Unlike many similar structures neither tube uses steel.

07/05/04

Ascending from the tube, traffic comes up on the west side of the Oakland Inner Harbor Channel.

07/05/04

As California 260 emerges from the Webster Street Tube, the highway approaches an exit for Mariner Square Drive and Marina Village Parkway.

04/04/04

California 260, which is signed as California 61, reaches a right exit to Mariner Square Drive and a left exit to Constitution Way / Marina Village Parkway.

04/04/04

As California 260 enters the downtown area of Alameda, the highway changes from a limited access/substandard freeway into a city street.

04/04/04

Southbound California 160 (Webster Street) at Santa Clara Avenue.

04/04/04

Southbound California 260 comes to its end at the point where Webster Street meets Central Avenue. Official state maps and legislation still consider a northern extension of California 61 north from this point to somewhere near the Maze interchange, but such a highway is very unlikely to be constructed.

04/04/04