In 2011, a construction project rebuilt the elevated freeway ramp at the south end of the Golden Gate Bridge, formerly known as Doyle Drive. Senior bridge engineer John Walters tours some of the new seismic technologies, including a seismic joint designed to handle several feet of longitudinal movement and a spherical bearing that allows for three-dimensional movement. Walters also points out a temporary structure built over the historic Presidio Pet Cemetery to protect the grave sites while providing a platform for the construction overhead.