Southern Alameda County Integrated Rail Analysis (SoCo Rail) Study

The Southern Alameda County Integrated Rail Analysis (SoCo Rail) Study is the first step in developing an East Bay passenger rail hub.

San Joaquin Regional Rail Commission (SJRRC)

Evaluating Rail Needs & Building Connectivity

The Southern Alameda County Integrated Rail Analysis (SoCo Rail) Study reviews the needs of current rail passengers in southern Alameda County and throughout the Northern California megaregion, and looks for ways to improve rail connections and connections with bus service.

The goal of the study is to identify and complete initial planning for an East Bay rail hub that could serve passengers within the next 10 years.

View the SoCo Rail Study Phase 1 and Phase2 Reports and their Appendices at the bottom of this page.

Building On a Statewide Vision

The 2018 California State Rail Plan (CSRP) established a vision for an integrated statewide passenger rail and express bus network, and calls for a rail hub station in southern Alameda County.

The SoCo Rail Study builds on the vision of the 2018 CSRP by identifying potential East Bay hub locations in order to recommend a hub option to be part of the northern California megaregional passenger rail network. The SoCo Rail Study identifies the rail hub location included in the Draft 2023 California State Rail Plan and advances the planning and development of a project that meets the study’s goals to improve regional rail connectivity in the Northern California megaregion.

Two Project Phases

The SoCo Rail Study was completed in two project phases.  Phase 1 of the SoCo Rail Study identified the Union City Intermodal Station as the recommended location for the East Bay rail hub. In coordination with Union City and other study stakeholders, Phase 2 of the SoCo Rail Study developed details for the project to extend Altamont Corridor Express (ACE) intercity passenger rail service to the Union City Intermodal Station, the Union City Intermodal Station Phase 3 Project.

Phase 1 Findings

The Phase 1 planning effort looks at current and future transportation and land use conditions, and evaluates the feasibility of potential East Bay hub station locations.

Key findings from the SoCo Rail Study Phase 1 Report for the mid-term (approximately 10 years) include:

  • Based on infrastructure constraints along the Coast Subdivision between Newark and Santa Clara via the Alviso Wetlands, the ability to provide additional passenger rail service to San Jose beyond the planned one additional round-trip for Altamont Corridor Express (ACE) is not possible without extensive upgrades to the Coast Subdivision. This is unlikely in the mid-term horizon due to cost and complexity.
  • Given capacity constraints along the Coast Subdivision and the time it would require for capacity improvements, an East Bay hub would provide a great opportunity to run additional passenger rail trains that could terminate in southern Alameda County without having to trigger large-scale improvement along the Coast Subdivision.
  • An East Bay hub would provide regional connections to rail and bus networks, allowing mega-regional rail services to have regional connectivity around the Bay Area.
  • San Joaquin Regional Rail Commission (SJRRC) supports turning back ACE trains in southern Alameda County at an East Bay hub as a strategy for increasing service in the mid-term horizon.
  • Capital Corridor Joint Powers Authority (CCJPA) is not planning to turn back trains in southern Alameda County, so improvements would be needed along the Coast Subdivision to provide additional service to San Jose.
  • A new passenger rail service along the Dumbarton corridor is infeasible in the mid-term due to constraints at Redwood City and capacity along the peninsula.
  • In the mid-term horizon, enhanced transbay bus services via the Dumbarton Bridge to the peninsula market can provide connectivity to both ACE and Capitol Corridor services in southern Alameda County. These enhanced transbay bus services could serve the East Bay hub(s).

Phase 1 Recommendations

SoCo Rail Study Phase 1 Recommendations are as follows:

  1. Based on analysis conducted during Phase 1 of the SoCo Rail Study, the Union City BART East Bay hub is recommended as the only “rail-to-rail” hub concept for the mid-term horizon (approximately 10 years) in order to:
    • Allow for additional ACE service into the Bay Area;
    • Provide ACE-BART connection; and
    • Ensure the highest level of connectivity to key travel markets throughout the Bay Area.
  2. To begin project implementation of Union City BART East Bay Hub, immediately pursue detailed planning and initial project development as part of Phase 2 of the SoCo Rail Study.
  3. The other East Bay hub concepts studied during Phase 1 of the SoCo Rail Study for the mid-term horizon — which include Ardenwood, Fremont-Centerville, Newark Junction, South of Newark, Shinn Junction and Warm Springs BART concept — are not recommended for further study as part of Phase 2 of the SoCo Rail Study.

Phase 2 Planning Overview

Phase 2 is a detailed planning effort which included initial project development of the East Bay hub concept recommended in Phase 1. Station, alignment and service planning details have been developed from comprehensive ridership and operational analyses. Phase 2 also included the development of a project implementation plan, and considerations included:

  • Development of conceptual operations plan
  • Modeling of the estimated ridership for the increase in ACE trains to the Union City East Bay hub concept
  • Conducted an equity analysis
  • Identification and conceptual design of infrastructure improvements
  • Developed rough order of magnitude capital and operating cost estimates
  • Established a conceptual level funding and financing plan
  • Created an implementation plan outlining steps for project development and opening service


Phase 2 Recommendations

The SoCo Rail Study Phase 2 recommendations are as follows:

  1. San Joaquin Regional Rail Commission (SJRRC) to advance the Union City Intermodal Phase 3 Project to the environmental clearance and preliminary engineering phase
  2. Extension of ACE rail service to the Union City Intermodal Station consisting of three daily intercity round trips in the mid-term horizon (approximately 10 years) focusing on non-commute trips (7 days a week service)
    1. One round trip between Union City and Chico
    2. Two round trips between Union City and Merced, allowing a timed connection to high-speed rail
  3. New ACE Intercity Rail platform, station track and layover facility at the Union City Intermodal Station
  4. Opportunities for multimodal connectivity at the Union City Intermodal Station between intercity rail and BART, local buses, transbay buses and active transportation

Benefits of the Phase 2 Recommended Project

  • Expands rail access and connectivity at a megaregional scale by linking ACE directly with BART, providing attractive transit options between the Bay Area and the Central Valley
  • Secures a critical rail-to-rail link between the Bay Area and the High-Speed Rail Early Operating Segment, maximizing the benefits of California’s transformational investment in a fast intercity rail network
  • Establishes a rail-to-rail hub in Southern Alameda County as envisioned in the State Rail Plan, building on over 20 years of ongoing transit-focused investment at the Union City Intermodal Station
  • Furthers progress on California’s climate and housing goals by supporting transit-oriented development in the Union City Station District and shifting away from reliance on fossil fuels
  • Improves equity by providing daily intercity service (including weekends and holidays) for transit-dependent riders, using zero-emissions trains that reduce greenhouse gas emissions, improve air quality and take cars off roads

Collaborative Goals

The SoCo Rail Study goals below have been developed through collaboration with regional partners and stakeholders to:

  • Enhance regional connectivity and increase equitable access
  • Enhance service reliability and safety
  • Promote sustainability and resiliency
  • Serve surrounding communities and shape growth
  • Develop feasible infrastructure improvements

Staff Contact

Kara Vuicich, AICP, Principal Planner/Analyst
Phone: 415-820-7928
Email: kvuicich@bayareametro.gov


The SoCo Rail Study is being led by MTC in partnership with the following partners:


  • City of Union City
  • Fremont
  • Newark

Regional Agencies

  • San Joaquin Regional Rail Commission (SJRRC)
  • California State Transportation Agency (CalSTA)
  • California State Department of Transportation (Caltrans)
  • Alameda County Transportation Commission (Alameda CTC)
  • Capital Corridor Joint Powers Authority (CCJPA)

Transit Agencies

  • San Francisco Bay Area Rapid Transit (BART)
  • San Mateo County Transit District (SamTrans)
  • Peninsula Corridor Joint Powers Board (PCJPB)
  • Tri-Valley - San Joaquin Valley Regional Rail Authority
  • Santa Clara Valley Transportation Authority (VTA)
  • California High-Speed Rail Authority (CHSRA)