The iconic Golden Gate Bridge is a suspension bridge spanning the Golden Gate, the opening of the San Francisco Bay into the Pacific Ocean, and linking the city of San Francisco to Marin County.
Before the Golden Gate Bridge was built, the only way to get across San Francisco Bay was by ferry. The ferry crossing between the Hyde Street Pier in San Francisco and Sausalito in Marin County took approximately 20 minutes and cost $1.00 per vehicle, a price was later reduced to compete with the new bridge. In the 1920s, engineer and bridge-builder Joseph Strauss became convinced that a bridge should be constructed across the Golden Gate.
The engineering challenge was enormous. The Golden Gate Bridge area often has winds of up to 60 miles per hour, and strong ocean currents sweep through a rugged canyon below the surface. Plus it was the middle of the Great Depression, funds were scarce, and the San Francisco Bay Bridge was already under construction. Strauss spent more than a decade drumming up support in Northern California, and Golden Gate Bridge history began when San Francisco voters overwhelmingly approved $35 million in bonds to construct the Golden Gate Bridge.
The now-familiar art deco design and International Red color were chosen, and construction began in 1933. The Golden Gate Bridge project was completed in 1937. Strauss was a pioneer in building safety, making history with innovations including hard hats and daily sobriety tests. He was innovated with the use of movable safety netting beneath the construction site, which saved the lives of many. Of the 11 men killed from falls during construction, 10 were killed 
when the net failed under the stress of a scaffold that had fallen. Nineteen others who were saved by the net over the course of construction became proud members of the “Halfway to Hell Club.” The low number of deaths was an outstanding accomplishment in an era when one man was killed on most construction projects for every million spent.
THE FIGURES
To build the pier supporting the South Tower, they first built a fender in this torrent of water. Then they pumped 35.6 million liters of water out of the fender and filled it with cement. The total weight of this anchorage is 60,000 tons.
The two towers rise up 746 feet above the water. The length of the suspension span is 1.2 miles. The roadway is suspended 220 ft above high water. The total combined weight of the bridge today is 887,000 tons
The cables connecting each end of the bridge are actually 27,572 wires woven together six wires at a time. The individual wires are the size of a pencil. 80,000 miles of wire were used to make the cables. The finished cables are three feet thick.
The original roadway was made with concrete. The weight was reduced by 12,300 tons in 1986 when a new roadway of lightweight steel decking covered in epoxy cement was installed. The bridge was designed to be very flexible. It can swing an amazing 27 feet and flex 10 feet under a big load. 
Today the Golden Gate Bridge has 40 million crossings per year. There have been over 1.8 billion vehicle crossings since its opening. The toll was 50 cents each direction in 1937. The toll is now five dollars.
The cost of the Golden Gate Bridge is estimated at $1.3 billion in today’s dollars.
The last of the construction bonds were retired in 1971, with $35 million in principal and nearly $39 million in interest raised entirely from bridge tolls.
