San Francisco Transbay Terminal
The San Francisco Transbay Terminal was a major regional transportation facility in downtown San Francisco, California, that operated from 1939 until its closure in 2010.[1] Designed by architect Timothy L. Pflueger in the Art Moderne style, the terminal initially functioned as the western endpoint for Key System interurban electric trains traversing the San Francisco–Oakland Bay Bridge, serving peak commuter volumes of up to 17,000 passengers every 20 minutes and handling over 26 million riders annually at its height during World War II.[2][3][4][5] Following the termination of rail operations in 1958 due to competition from automobiles and emerging highway infrastructure, the terminal was repurposed as a bus depot, accommodating services from operators such as AC Transit, Golden Gate Transit, and SamTrans for East Bay and Peninsula commuters.[6] Its design capacity supported up to 35 million passengers per year, reflecting prewar optimism in mass transit amid dense urban travel demands, though actual usage declined with postwar suburban sprawl and the advent of BART in the 1970s.[2] The terminal's demolition began in August 2010 to clear the site for the contemporary Salesforce Transit Center, highlighting the shift from mid-20th-century rail-bus hybrids to modern multimodal hubs integrated with high-speed rail plans like California HSR.[1] Despite its functional obsolescence, the structure exemplified streamlined architectural efficiency tailored to industrial-era commuting patterns.[7]Original Terminal (1939–2010)
Design and Construction
The original San Francisco Transbay Terminal was designed by architect Timothy L. Pflueger as an intermodal facility to serve commuter rail traffic crossing the San Francisco–Oakland Bay Bridge, connecting San Francisco to the East Bay and beyond.[8][4] In the Art Moderne style, the structure featured streamlined forms emphasizing functionality and modern efficiency, reflecting the era's shift toward automobile and rail integration.[9] The terminal was constructed by the California Toll Bridge Authority at First and Mission streets, funded through Bay Bridge toll revenues of 50 cents per automobile, and opened on January 14, 1939.[10] Engineering integrated the terminal with the Bay Bridge's lower deck rail lines, including loop ramps for direct train access without street-level crossings, accommodating operations by the Key System and other carriers.[10] The design supported high-capacity service, rated for 35 million annual passengers with a peak 20-minute throughput of 17,000 commuters via 10-car trains dispatched every 63.5 seconds.[2][10] Construction aligned with the bridge's completion, enabling electric-powered interurban trains to terminate in downtown San Francisco rather than at ferry slips.[11] Pflueger collaborated with Arthur Brown Jr. and John Donovan on aspects of the modern design, prioritizing durable materials suited for heavy transit use, though specific building elements like concrete framing and steel reinforcements were standard for the period's seismic considerations in the Bay Area.[12] The facility's layout included a central concourse for passenger flow, with provisions for future expansion, though rail service ceased in 1958, leading to its conversion for buses.[6] Post-World War II, it handled up to 26 million passengers yearly before decline.[2]Rail Service and Operations
The original Transbay Terminal facilitated electric interurban rail service across the San Francisco–Oakland Bay Bridge, commencing operations on January 15, 1939, as its primary western terminus.[13] Constructed with 11 stub-end tracks accommodating bi-level boarding platforms, the facility supported peak throughput of 17,000 passengers every 20 minutes, targeting an annual capacity of 35 million riders.[2] Trains accessed the terminal via dedicated lower-deck trackage on the bridge, transitioning from electrified third-rail segments in the East Bay to overhead catenary wires approaching San Francisco.[6] Service was dominated by the Key System Transit Company, which routed lines A, B, C, E, F, and G from East Bay hubs including Oakland, Berkeley, and Richmond directly into the terminal. Initially supplemented by Sacramento Northern Railway and Interurban Electric Railway trains from northern East Bay and Vallejo areas, these ancillary operators ceased passenger service by late 1941 amid financial losses and shifting ridership to automobiles.[14] Key System trains, comprising steel interurban cars with capacities of 100–150 passengers each, operated at frequencies up to every 5–10 minutes during rush hours, peaking at over 200,000 daily boardings across the system before 1958.[15] World War II gas rationing temporarily boosted demand, with daily transbay rail usage exceeding 40,000 by 1944, but postwar highway expansions and private vehicle adoption—facilitated by federal interstate funding—eroded viability.[6] Maintenance costs for aging infrastructure and bridge trackage further strained operations, prompting the Key System's parent, National City Lines, to prioritize buses. Rail service concluded on April 20, 1958, with all Key System electric trains replaced by AC Transit diesel buses using the bridge's upper deck.[16] Track removal followed promptly, converting the terminal to bus-only use without provisions for rail resumption.Conversion to Bus-Only Service
The San Francisco Transbay Terminal's transition to bus-only service followed the discontinuation of interurban rail operations by the Key System on April 20, 1958, after the lower deck of the San Francisco–Oakland Bay Bridge was reconfigured exclusively for automobile traffic, eliminating rail tracks.[2] This shift reflected broader postwar preferences for highway expansion over rail transit, leading to the formation of AC Transit to replace Key System bus and rail services with diesel buses.[15] In 1959, the terminal was fully converted to accommodate bus operations, with its 21 rail platforms repurposed into bus bays to handle regional services crossing the Bay Bridge.[13] AC Transit became the primary operator, utilizing the facility for routes from Alameda and Contra Costa counties, while other agencies including Golden Gate Transit and SamTrans also integrated services, connecting passengers to points north and south.[11] The upper decks were adapted for bus loading and unloading, supporting peak-hour commuter flows that exceeded 50,000 daily passengers by the 1960s.[6] This conversion marked the end of the terminal's multimodal role, as Peninsula rail services via Southern Pacific had never utilized the facility, terminating instead at stations like Third and Townsend.[15] The change facilitated seamless bus transfers but highlighted the infrastructure's underutilization of its original rail capacity, contributing to long-term debates on transit efficiency amid growing automobile dependency.[2]Decline, Closure, and Demolition
Following the discontinuation of rail service in 1958 by Southern Pacific, which ended the Peninsula Commute trains due to rising automobile usage after World War II, the Transbay Terminal transitioned to bus-only operations, marking the onset of its decline.[6] Peak ridership of 26 million passengers annually at the war's end plummeted as gas rationing lifted and personal vehicles proliferated, reducing the facility's relevance.[2] By the late 20th century, the terminal had deteriorated into a rudimentary bus depot, with boarded-up businesses, vanishing amenities, and inadequate maintenance exacerbating its obsolescence.[17] The 1989 Loma Prieta earthquake inflicted heavy damage on the terminal and surrounding infrastructure, heightening seismic vulnerabilities in the 1939 structure that predated modern building codes.[18] Assessments determined that retrofitting the aging facility to withstand a maximum credible earthquake was impractical, especially given its inability to support planned underground rail extensions for Caltrain.[19] These factors, combined with failure to meet contemporary seismic standards and insufficient capacity for projected transit demand, rendered the terminal unsuitable for continued use.[20] The terminal closed on August 7, 2010, coinciding with the opening of a temporary facility to handle bus services during redevelopment.[21] Demolition commenced on December 3, 2010, using wrecking balls to dismantle the 71-year-old structure, clearing the site for the new transit center.[22] Full demolition was completed by September 7, 2011, eliminating the seismically deficient building and enabling construction of a modern replacement.[23]Replacement Project Planning and Temporary Facilities
Initial Planning and Funding Challenges
The Loma Prieta earthquake on October 17, 1989, severely damaged the original Transbay Terminal, prompting initial assessments for seismic retrofitting and revitalization to meet modern accessibility and safety standards, but comprehensive replacement planning faced immediate setbacks due to the absence of a viable funding mechanism.[13] Throughout the 1990s, efforts to advance a Caltrain downtown extension and terminal rebuild stalled repeatedly, as proposals—including one from Mayor Frank Jordan for a scaled-down facility—lacked dedicated financial backing, leaving the project in limbo despite growing recognition of the terminal's obsolescence after rail services ended in 1958.[13] In November 1999, San Francisco voters approved Proposition H, which mandated the extension of Caltrain service to a new or rebuilt Transbay Terminal site, providing a policy foundation but not immediate capital; this measure aimed to integrate regional rail with bus operations but highlighted ongoing fiscal hurdles, as implementation required novel financing like the sale of surplus state properties and value capture from surrounding redevelopment.[13] To address coordination among disparate agencies, the Transbay Joint Powers Authority (TJPA) was established on April 4, 2001, comprising representatives from the City and County of San Francisco, Alameda Contra Costa Transit District (AC Transit), and the Peninsula Corridor Joint Powers Board, tasked with overseeing planning, design, construction, and operation of the multi-modal transit center.[24] [8] Early funding remained precarious, with the TJPA securing an initial $9.375 million from federal sources to initiate studies, but broader capital for the estimated $1.6 billion Phase 1—encompassing the transit center replacement—depended on delayed federal appropriations and state land sales projected to yield around $429 million by 2010.[25] [26] Progress was further impeded by the need for extensive environmental impact reviews, culminating in the Federal Transit Administration's Record of Decision on February 8, 2005, following the Final Environmental Impact Statement/Environmental Impact Report; only then did the project receive $55 million in federal funding via the Safe, Accountable, Flexible, Efficient Transportation Equity Act (SAFETEA-LU).[13] [8] These delays underscored systemic challenges in aligning local, state, and federal commitments for large-scale infrastructure, where fragmented authority and reliance on earmarks protracted the path from concept to groundbreaking.[13]Temporary Transbay Terminal Operations
The Temporary Transbay Terminal opened in August 2010 to replace the original facility after its closure on August 7, 2010, providing interim accommodations for transbay bus passengers amid the demolition of the old terminal and construction of the permanent Salesforce Transit Center.[13][27] Situated on the downtown block bounded by Main, Folsom, Beale, and Howard streets, the modular structure featured open-air bus bays, basic passenger shelters, ticketing areas, and restrooms designed for efficient bus turnaround without extensive amenities.[28] Operations centered on regional bus services crossing the San Francisco–Oakland Bay Bridge and other routes, handling peak commuter flows during weekday mornings and evenings.[24] The terminal supported multiple operators, including AC Transit for East Bay routes, Golden Gate Transit for North Bay connections, SamTrans for Peninsula services, WestCAT Lynx for select express lines, San Francisco Municipal Railway (Muni) for local extensions, and Greyhound for intercity travel.[28][24] Buses accessed the site via dedicated ramps from nearby streets, with coordination managed by the Transbay Joint Powers Authority to minimize disruptions despite the facility's exposed design and limited capacity compared to predecessors.[13] The terminal operated continuously without major service interruptions until August 12, 2018, when transbay buses shifted to the newly opened Salesforce Transit Center.[27] However, following the discovery of structural fissures that shuttered the new center in September 2018, bus operations briefly resumed at the temporary site, with Muni and regional carriers rerouting services there until repairs allowed full resumption at the permanent facility in 2019.[29] This extension underscored the temporary terminal's role as a reliable contingency amid the replacement project's challenges.[13]Transition and Demolition Aftermath
Transit operations at the original Transbay Terminal concluded on August 7, 2010, with all bus services transitioning to the newly opened Temporary Transbay Terminal located adjacent to the site.[13][21] This shift accommodated operators including AC Transit, Golden Gate Transit, SamTrans, and Muni, maintaining regional connectivity without interruption despite the temporary facility's more rudimentary design featuring open-air boarding areas.[8] Demolition of ancillary structures, such as Bay Bridge ramps, commenced on August 14, 2010, followed by the systematic dismantling of the terminal building itself.[30] The demolition process, managed by the Transbay Joint Powers Authority (TJPA), spanned from late 2010 through September 2011, involving nearly 55,000 labor hours and resulting in no lost-time safety incidents.[13] Over 7,500 tons of steel and 92,000 cubic yards of concrete were recycled from the site, equivalent to filling 28 Olympic-sized swimming pools with the concrete alone, supporting environmental sustainability goals in the project.[31] The effort stayed on schedule and within budget, clearing the 19-acre parcel for foundational work on the replacement Salesforce Transit Center.[13] In the aftermath, the vacated site enabled immediate site preparation activities, including utility relocations and groundwork for new high-rise developments under the Transbay Redevelopment Plan, generating construction jobs in the Bay Area.[32] Transit volumes initially held steady via the temporary terminal, though its limited capacity—handling up to 1,500 buses daily—prompted calls for expansions to address peak-hour crowding.[28] No significant long-term disruptions to regional bus services were reported, as the temporary setup preserved essential east-west links across the Bay Bridge until the permanent center's completion.[5] The demolition also facilitated archaeological surveys, uncovering artifacts from the site's pre-terminal history, which were documented prior to full excavation.[33]Salesforce Transit Center Construction and Opening
Design Features and Engineering
The Salesforce Transit Center, designed by Pelli Clarke Pelli Architects with Adamson Associates as architect of record, incorporates a multi-level structure exceeding 1,000,000 square feet, featuring an elevated two-block-long bus deck that supports regional and intercity bus operations while permitting street traffic to pass underneath, thereby reconnecting divided neighborhoods.[31][34] The design centers on a grand oval atrium, or Grand Hall, rising 70 feet high, illuminated by a signature central light column that funnels natural daylight to subterranean levels through glazed shafts, reducing reliance on artificial lighting.[34][35] The rooftop, elevated 70 feet above the street, hosts a 5.4-acre public park spanning 1,400 feet, equipped with walking trails, an amphitheater, botanical gardens, and play areas, functioning dually as a recreational space and a green roof for stormwater filtration and urban heat mitigation.[31][34] Structurally, the center employs a space-frame canopy roof composed of approximately 800 undulating, perforated aluminum panels in a Penrose tiling pattern, fabricated from pearlescent white metal to evoke a light, cloud-like appearance while providing shade and aesthetic complexity enhanced by an LED art installation.[34] Structural engineers Thornton Tomasetti and Schlaich Bergermann Partner integrated cast steel nodes—totaling around 3.5 million pounds across 75 unique geometries, each weighing 4,400 to 44,600 pounds—into the architecturally exposed perimeter framing and light column, serving critical roles in both gravity load support and seismic force resistance tailored to San Francisco's earthquake-prone environment.[36] The bus deck and overall frame utilize natural ventilation systems to manage bus exhaust and passive climate control, minimizing energy use.[34][31] Sustainability features underpin the engineering, achieving LEED Gold certification through innovations such as the rooftop park's native plantings and efficient irrigation that halve potable water consumption, integrated drainage for rainwater reuse, and light columns that optimize daylight penetration to cut electricity demands for interior lighting.[31][34] The facility accommodates 11 transit systems with direct freeway ramps for efficient bus access, designed to handle up to 100,000 daily passengers.[31] These elements combine to create a resilient, multimodal hub that prioritizes environmental efficiency and structural integrity.[36][34]Construction Timeline and Cost Overruns
Construction of the Salesforce Transit Center's Phase 1, encompassing the bus terminal and foundational "train box" for future rail extensions, commenced in 2010 after demolition of the original Transbay Terminal began in the same year, with the latter phase concluding on schedule and within budget after recycling substantial materials including 7,500 tons of steel.[13] The project spanned approximately eight years, marked by sequential advancements such as the initial concrete pour for the permanent foundation on September 5, 2013, and the assembly of the steel superstructure starting in November 2014.[8][13]| Milestone | Date |
|---|---|
| Demolition of original terminal begins | 2010[13] |
| First concrete pour for foundation | September 5, 2013[8] |
| Steel superstructure assembly starts | November 2014[13] |
| Substantial completion | 2018[13] |
| Grand opening and initial bus service | August 12, 2018[37] |