to the low bid of by a joint venture between Peter Kiewit Sons' Co. — A. Soda & Son — Judson Pacific Murphy Corp. The substructure construction moved rapidly, with an estimated 45% of piers completed approximately a year after the contract was awarded. The bridge was completed in 1956. It was dedicated on August 31, and opened for traffic on September 1. At the time, it was the world's second-longest bridge, behind the San Francisco–Oakland Bay Bridge, as well as the longest continuous steel bridge. Historical notes Originally a part of State Route 17, the bridge is now part of Interstate 580. Upon its opening, the Richmond–San Rafael bridge was the last bridge across San Francisco Bay to replace a previous ferry service, leaving the Benicia–Martinez Ferry across Carquinez Strait as the only remaining auto ferry in the Bay Area (it would be replaced by a bridge in 1962). Description The bridge—including approaches—measures 5.5 miles (29,040 feet / 8,851.39 m / 8.9 km) long. At the time it was built, it was one of the world's longest bridges. The bridge spans two ship channels and has two separate main cantilever spans. Both main cantilever spans are raised to allow ship traffic to pass, and in between, there is a "dip" in the elevation of the center section, giving the bridge a vertical undulation or "roller coaster" appearance and also the nickname "roller coaster span". To save money, the cantilever main spans share identical symmetric designs, so the "uphill" grade on the approach required for the elevated span is duplicated on the other "downhill" side, resulting in a depressed center truss section. In addition, because the navigation channels are not parallel to each other, the bridge also does not follow a straight line. This appearance has also been referred to as a "bent coat hanger". After it was completed, many were disappointed by the appearance of the bridge; Frank Lloyd Wright, a famous designer who was not an engineer, reportedly called for it to be destroyed due to its ugliness, and complained that it was "the most awful thing I've ever seen" during its construction in 1953. Contrariwise, the neighboring Golden Gate Bridge, and the western span of the Bay Bridge, had been considered engineering and historical marvels. However, the project's senior engineers were the same ones who had worked on the Bay Bridge, with their design reflecting lessons they