<P> Modern knowledge of the effect of earthquakes on structures led to a program to retrofit the Golden Gate to better resist seismic events . The proximity of the bridge to the San Andreas Fault places it at risk for a significant earthquake . Once thought to have been able to withstand any magnitude of foreseeable earthquake, the bridge was actually vulnerable to complete structural failure (i.e., collapse) triggered by the failure of supports on the 320 - foot (98 m) arch over Fort Point . A $392 million program was initiated to improve the structure's ability to withstand such an event with only minimal (repairable) damage . One challenging undertaking is completing this program without disrupting traffic . A complex electro - hydraulic synchronous lift system was custom built for construction of temporary support towers and a series of intricate lifts, transferring the loads from the existing bridge onto the temporary supports . This was completed with engineers from Balfour Beatty and Enerpac, accomplishing this task without disrupting day - to - day San Francisco commuter traffic . The retrofit was planned to be completed in 2012 . </P> <P> The former elevated approach to the Golden Gate Bridge through the San Francisco Presidio, known as Doyle Drive, dated to 1933 and was named after Frank P. Doyle, President and son of the founder of the Exchange Bank in Santa Rosa, and the man who, more than any other person, made it possible to build the Golden Gate Bridge . The highway carried about 91,000 vehicles each weekday between downtown San Francisco and the North Bay and points north . The road was deemed "vulnerable to earthquake damage", had a problematic 4 - lane design, and lacked shoulders, and a San Francisco County Transportation Authority study recommended that it be replaced . Construction on the $1 billion replacement, temporarily known as the Presidio Parkway, began in December 2009 . The elevated Doyle Drive was demolished on the weekend of April 27--30, 2012, and traffic used a part of the partially completed Presidio Parkway, until it was switched onto the finished Presidio Parkway on the weekend of July 9--12, 2015 . As of May 2012, an official at Caltrans said there is no plan to permanently rename the portion known as Doyle Drive . </P> <P> As a prominent American landmark, the Golden Gate Bridge has been used in numerous media which includes books, films and video games . </P>

Who built and designed the golden gate bridge