In an interview with ShortList, San Andreas director Brad Peyton said his interest in the film started with discussions with producers looking to replicate the success of Peyton's first feature with Dwayne Johnson, Journey 2. Peyton said the original script for San Andreas was "a bit rough, but the concept was there." What appealed to him about the project was its potential as a blockbuster disaster film that was grounded in the intimate story of a blue-collar family reconciling. Peyton said, "The fact that you could have the epic nature and the intimacy at the same time was something you don't always get."
From the opening scene, Peyton provokes waves of anxiety and relief in the viewer by putting characters in life-threatening situations before they are rescued. When a young driver reaches for a water bottle as the viewer sees an oncoming truck, the audience recoils with the fear of knowing she is narrowly avoiding a crash. Peyton translates this suspense into a misdirection when the woman doesn't crash into another car but is pushed off the road by tumbling rocks—something she and the audience couldn't have prepared for. The tension only abates when Ray pulls the woman from her car just before it falls into a ravine.
Peyton also uses camera movements to elevate the chaos in the film. In the rooftop lunch scene with Emma and Susan, an earthquake hits and the viewer sees people running wild for safety. Rather than remaining stationary, Peyton's camera tracks terrified patrons in one direction and then sharply moves to track another in an opposing direction, immersing the viewer in the characters' panic. In this and other thrilling scenes in which characters narrowly escape death, Peyton depicts his main cast engaging in intimate conversations in which they work through their emotions and prepare themselves for the next challenge.
While the film depicts a natural disaster more destructive than any earthquake the world has known, Peyton wanted to make sure the CGI visual effects were based on reality. "We had professors at UCLA look at the script," he told ShortList, "we had seismologists look at the script. We got their notes, how would this happen, how could we do this. All of the lingo, all the equipment from Paul Giamatti's character: all that stuff is real." Peyton explained that even though the film was a major Hollywood movie designed to be entertaining above anything, he wanted to ground the visual effects with references to real-life examples of buildings collapsing, tsunamis rising, and streets splitting open. Peyton believed that a lack of realism in the visuals would inhibit the audience's ability to "feel" the emotions stirred up by the film. Justifying his research into the visuals, Peyton said, "Even if I have to bend it a little bit or exaggerate it a little bit, I know it's real, so I can make an educated decision about how to exaggerate it."
