California State Route 905 follows the Otay Mesa Freeway east across southern San Diego from Tocayo Avenue and Interstate 5 in the San Ysidro area to the International Border at Otay Mesa. A major commercial route, SR 905 is the main gateway for trucks into Mexico, as trucks are prohibited at the San Ysidro Port of Entry connecting with I-5/805. Despite completion of the freeway from I-5 to the Otay Mesa port of entry on July 30, 2012, the Otay Mesa Freeway remains a state route.
Per an agreement between the California Department of Transportation (Caltrans) and the Federal Highway Administration (FHWA), it is expected that SR 905 will be upgraded to Interstate 905 in the future. FHWA informally approved nonchargeable Interstate status for the route, and the American Association of State Highway and Transportation Officials (AASHTO) approved the designation of Interstate 905 on December 7, 1984. Correspondence between Caltrans and AASHTO on October 24, 1984 requested Interstate 905 as follows:
Designation of a segment of State Route 117 and a segment of State Route 125 as I-905 between I-5 in San Diego and the International Border at Tijuana, Mexico.
(This route is 8.8 miles in length and will connect to a new border crossing which will relieve the congestion at the existing Interstate 5, San Ysidro crossing.)
California State Route 905 is part of High Priority Corridor 30: Camino Real for its entire length.
Otay Mesa was expanded to six lanes by 2000 with $20 million in state and local funds.1 The first section of SR 905 upgraded to freeway standards east of San Ysidro was the interchange with Siempre Viva Road (Exit 9). This exchange was completed in 2005. Upgrades for the remainder of SR 905 were originally slated for 2006 or 2007, but funding constraints partitioned construction into four separate projects.
Costing $441 million, work on SR 905 commenced with Phase 1A in April 2008. Phase 1A included construction of the six lane freeway between Siempre Viva Road and Britannia Boulevard on a new alignment south of Otay Mesa Road. It also upgraded SR 905 north of Exit 9 to Airway Road. It was completed in December 2010.1</sup
Underway from July 2009 to July 30, 2012, Phase 1B followed with construction of the six lane highway from Britannia Boulevard west to the previous freeway end near Interstate 805. Started in May 2011 and completed in February 2012, Phase 2 focused on improvements at the cloverstack interchange connecting SR 905 with I-805.1
Subsequent work added an interchange with SR 11, a toll road planned from SR 905 and SR 125 (South Bay Expressway) east to a new port of entry. A partial exchange was completed at SR 11/125/905 on November 30, 2016.2
A westerly extension of SR 905 through Border Field State Park and the Tia Juana River Valley was proposed legislatively. However, the extension remains unconstructed due to environmental concerns.