The year after the September 11 , 2001 attacks , the military erected a fence to block a deer tunnel underneath the freeway that connected the base and Mission Trails Regional Park , since the tunnel could be used to gain unauthorized access to the base . In 2006 , construction began to add a third lane on westbound SR 52 between Mast Boulevard and Santo Road . The expansion cost $ 3.4 million ( about $ in dollars ) and was funded by the state and the county TransNet sales tax . The new lane opened on May 8 , 2007 ; however , the widening generated complaints from angry commuters facing a " bottleneck " at Santo Road . Because the additional lane was constructed in portions , the opening of the third lane between Santo Road and the existing third lane closer to I-15 was delayed ; however , construction for the missing was approved in April 2007 . The extension opened on July 20 , 2007
September 11 , 2001 attacks
September 11 attacks
California State Route 52