The $9 million steel bridge structure will connect the Children's Hospital Los Angeles' two main campuses, the Anderson Pavilion and the Saban Research Institute.
Crews lifted the 40-ton bridge onto trailers Friday night to tow it three-tenths of a mile to the site, where it was hoisted onto two steel tower supports.
Traffic is being rerouted around affected streets.
The hospital remains open.
The "Bridge Over Sunset" walkway is scheduled to open to hospital staff, patients, and their families in February 2013.