Between Hayward and San Mateo and San José there are 12 to 36 inches (30 to 90 cm). The deepest part of the bay is located below and outside the Golden Gate Bridge, at 372 feet (113 m). The bridge has two sections of approximately the same length: the oldest western section, officially known as the Willie L. Bridge (in honor of former San Francisco mayor and president of the California State Assembly, Willie L.
Brown Jr. The western section is a double suspension bridge with two decks, westerly traffic is carried out on the upper deck and eastbound traffic is carried out on the lower deck. The largest stretch of the original eastern section was a cantilever bridge. The Oakland-side toll plaza (westbound only from 196) has eighteen toll lanes, and now all charges are collected through the FasTrak electronic toll collection system or through bills mailed through the USPS, based on the license plate of the car, according to Department of Motor Vehicle records.
The measurement signs are about 300 m (1000 ft) west of the toll plaza. Two lanes dedicated to full-time buses avoid toll booths and metering lights that surround the right (north) side of the toll plaza; other busy vehicles may use these lanes during work periods from Monday to Friday morning and afternoon. The two toll lanes on the far left are lanes for high-occupancy vehicles during travel periods from Monday to Friday. Radio and television traffic reports usually refer to congestion in the toll plaza, at traffic lights, or in a parking lot in the middle of the road for bridge employees; the parking lot is about 580 m (1900 ft) long and extends from about 240 m (800 ft) east of the toll plaza to about 100 feet (30 m) at the west of the traffic lights.
During morning commute hours, traffic congestion on the westbound access from Oakland extends across the MacArthur Maze crossing at the east end of the bridge to the three secondary highways, Interstate 580, Interstate 880 and I-80 in the direction of Richmond. Because the number of lanes on the eastbound access road from San Francisco is structurally restricted, eastbound setbacks are also common during nighttime travel hours. The bottleneck in the east direction is not the bridge itself, but the access, which has only three lanes in each direction, in contrast to the five on the bridge. The highway ramps next to the tunnel provide access to the Djerba Islands Buena and Treasure.
As the toll plaza is on the Oakland side, the western section is in fact a toll-free bridge; traffic between the island and the main part of San Francisco can cross freely from one side to the other. Those traveling only from Oakland to Yerba Buena Island, and not all the way to the main part of San Francisco, will have to pay the full toll. Box-shaped diagonal beams have been added to each bay on the upper and lower decks of the western openings. These add stiffness to reduce movement from one side to the other during an earthquake and reduce the likelihood of damage to roof surfaces.
The western accesses have also been partly modernized, but have mostly been replaced by new reinforced concrete constructions. The San Francisco Bay Area Water Trail is a planned system of designated starting points to improve access to the bay on small, non-motorized boats. Parks and protected areas around the bay include the Eden Landing Ecological Reserve, Hayward Regional Shore, San Francisco Don Edwards Bay National Wildlife Refuge, Hayward Shoreline Interpretation Center, Crown Memorial State Beach, Eastshore State Park, Point Isabel Regional Shore, Brooks Island Regional Reserve, and César Chávez Park. Large ships transiting the bay must follow deep underwater channels that are maintained by frequent dredging, since the average depth of the bay is as deep as that of a pool, approximately 12 to 15 feet (4 to 5 m).During the 20th century, the bay was subject to the Reber Plan of the 1940s, which would have filled in parts of the bay to increase industrial activity along the coast.
It is believed that the first European to enter the bay was the Spanish explorer Juan de Ayala, who crossed the Golden Gate on August 5, 1775 in his ship San Carlos and docked in a bay on Angel Island, now known as Ayala Cove. San Francisco Bay was the country's first wildlife refuge, Oakland's Merritt artificial lake, built in the 1860s, and the first urban national wildlife refuge in the United States, the Don Edwards San Francisco Bay National Wildlife Refuge (SFBNWR) in 1972. The first recorded European discovery of San Francisco Bay was on November 4, 1769, when Spanish explorer Gaspar de Portolá, unable to find the port of Monterrey, continued north near what is now Pacific and reached the top of the 1,200 foot (370 m) high Sweeney Ridge, now marked as the place where he first saw San Francisco Bay. You could sail across the bay until you reached San José until the 1850s, when hydraulic mining released enormous amounts of sediment from rivers that settled in parts of the bay that had little or no current. A coastal bike and pedestrian path known as the San Francisco Bay Trail surrounds the edge of the bay.
Foster City, Redwood Shores, Paradise Cay, and Emeryville's westward expansion were some of the last developments along the bay's shoreline before McAteer-Petris limited additional filling of the bay. The official name of the bridge, for all functional purposes, has always been the San Francisco-Oakland Bay Bridge, and most of the local population knows it simply as the Bay Bridge. The net effect of dredging has been to maintain a narrow and deep channel, perhaps deeper than the original bay channel, through a much smaller bay Profunda.se is developing the San Francisco Bay Area Water Trail, a growing network of launch and landing sites around the bay for users of small, non-motorized boats (such as kayakers). By the end of the 19th century, these patches had filled much of the bay's shallow plains, raising the entire profile of the bay.