1967 orthotropic bridge
With increased road and sea traffic, a bill was introduced in 1961 by State Senator Richard J. Dolwig to fund a new high-level fixed bridge to replace the 1929 lift bridge. The modern span, which began construction on July 17, 1961, opened to traffic in 1967 at a cost of $70 million ($447 million in 2017). The originally designed improvement would maintain the existing lift span (along with associated delays due to passing vessel traffic), adding a second deck to the truss spans and widening the existing traverses to four lanes,[12] but the California Toll Bridge Authority added US$30,000,000,000 ($213,700,000 in 2017) to the project budget in September 1961 to replace the existing lift span with a high level double deck fixed span,[12] which would have been similar in appearance to a lift span.[13].
By then, previous phases of the project had already been awarded to relocate the San Mateo to Hayward toll plaza to a new fill[14] and bids had been submitted for the new eastern trestle,[15] with construction of the trestle awarded to Peter Kiewit Sons.[16] The finished single-deck design was not completed until January 1962, with work estimated to have initially been completed in 1965.[17].
The new span won two awards in 1968: an ASCE Award for Outstanding Civil Engineering Achievement[18] and a bridge award from the American Institute of Steel Construction.
William Stephen Allen was hired as an architectural consultant,[17] although the bridge was designed by the Bay Toll Crossings Division (under the direction of Chief Engineer Norman C. Raab) of the California Department of Public Works. Chuck Seim, one of the design engineers working for Bay Toll Crossings, would later mention Allan Temko's criticism of Raab's economical truss design for the Richmond-San Rafael crossing for generating enough public pressure to push for the single-deck design. Temko's article cited T. Y. Lin as opposing a repeat of the Richmond-San Rafael design, but Lin ultimately gave Temko credit for the design. Raab retired and his successor, E. R. "Mike Foley, was willing to incorporate aesthetic considerations, resulting in the final design. The high-rise western span features a steel superstructure, with an orthotropic deck on two parallel box girders, following the construction of several smaller test bridges using the same orthotropic deck technology. It was the first large-scale use of an orthotropic deck, reducing weight, and therefore therefore seismic loading, although the bridge is expected to receive moderate to significant damage following an earthquake.[21].
Murphy Pacific Marine built the floating crane barge Marine Boss in 1966 with a capacity of 500 short tons (454 t) to carry the heavy box girder and deck section lifts.[22] The large lifting capacity of the Marine Boss allowed Murphy Pacific to lift prefabricated girders much longer than existing barge cranes would have allowed. The box girder and deck sections were fabricated at Murphy Pacific's Richmond "Richmond (California)" yard and were transported by Marine Boss to the bridge construction site.[23]Marine Boss was sold for scrap in 1988 to Weeks Marine in New Jersey,[24] who renamed her Weeks 533 and refitted her. Weeks 533 have since been used for several notable heavy lifts, including the transfer of the Concorde and Enterprise to the Intrepid Sea, Air & Space Museum and the lifting of the fallen hull of US Airways Flight 1549 from the Hudson River.
The total length of the bridge is 7 miles (11.3 km), which is made up of a 1.9-mile (3.1 km) high western span and a 5.1-mile (8.2 km) eastern trestle span. 425,000 cubic yards (324,936 m³) of fill was used at the Hayward end to reclaim land for the toll plaza and administrative buildings.[16] The eastern trestle span was built on 4,840 hollow prestressed concrete piles, each 60-90 feet (18-27 m) long.[16] The contractor constructed a foundry yard at Richmond to produce the concrete piles continuously. In 1963 the new eastern section of the trestle was completed[25] and traffic over the existing 1929 bridge was transferred to it.[26].
Work on the high-rise western section was put out to tender in October 1964[27] and began in 1965. It crosses a shipping channel, with an orthotropic main span 750 feet (229 m) long (at the time, the longest span in the United States)[13][26][27] and has a vertical clearance of 135 feet (41 m). The main span is flanked by two orthotropic lumbar spans each 375 feet (114 m) long, and there are seven orthotropic lateral spans on the approach to each lumbar span. Each of these side spans is 292 feet (89 m) long.[20] Although these spans appear to be formed by continuous box girders, they consist of alternating anchor spans and suspended spans. The anchor spans rest lightly on two adjacent piers and cantilevers on each side, and the suspended spans are hung between the ends of two adjacent anchor spans. There are nine additional 208-foot (63 m) steel spans carrying a concrete deck on the San Mateo side of the tall building, and ten steel spans carrying a concrete deck on the Hayward side, ranging from 186-208 feet. (57-63 m).[26] The bridge carries around 93,000 cars and other vehicles on a typical day, almost double its original projected design capacity of 50,000 vehicles per day.[27].
The bridge's steel deck, approximately 418,000 square feet (38,833 m²), was paved with a two-layer epoxy asphalt concrete surface. The San Mateo Bridge was the first deployment of an epoxy asphalt concrete wear surface. As of 2005, the original wear surface was still in use, but was later replaced in 2015.[31].
The high-rise section was initially built with six lanes and the eastern carriageway with four lanes (two in each direction). The section of roadway was a perennial traffic bottleneck until it was widened to six lanes in 2002, along with much-needed improvements to its connections to Interstate 880 in Hayward.
Bus service over the bridge is provided by AC Transit's Line M Transbay.
Power lines built by PG&E in the 1950s parallel the bridge across the bay.[32] They provide power to the peninsula and San Francisco ("San Francisco (California)").