SR 78 serves as the primary east-west travel corridor between Escondido and Oceanside, traversing through Carlsbad, Vista, and San Marcos, as well as unincorporated areas of San Diego County. It is the primary route for local and regional travel in North County and provides north-south connections to Interstates 5 and 15.
A study to evaluate plans to improve SR 78 was completed in 2012 and construction improvements just west of the SR 78/I-15 interchange were implemented. Visit the SR 78 Corridor Study project webpage to learn more.
SANDAG and Caltrans have proposed additional improvements to this corridor, including the I-5/SR 78 Interchange, I-15/SR 78 Express Lanes connectors, SR 78 HOV/Express Lanes, Woodland/Barham Interchange, and operational improvements along SR 78. Other projects include future double tracking and express services for the SPRINTER and the construction of additional segments of the Inland Rail Trail Bike Path.
