The Vineyard Driving Directions Exit Hwy 78 at Twin Oaks Valley Road. North on Twin Oaks Valley Road to San Marcos Blvd. Right on San Marcos (stay in center lane). Continue on San Marcos Blvd. across railroad tracks and across Mission Road. When crossing Mission Road, San Marcos Blvd. turns into Vineyard Road.  When road forks, bear to the right and continue on Vineyard Road. Sales Center is on the left (look for flags).