TRANSITMetro's A Line, still widely called the Foothill Gold Line, crossed from Los Angeles County's inner suburbs into the Pomona Valley on September 19, 2025, when the 9.1-mile Glendora-to-Pomona segment opened to revenue service. It is the longest light-rail extension that the Metro Gold Line Foothill Extension Construction Authority has delivered. This 2026 guide and analysis of the Foothill Gold Line Extension to Pomona and Montclair covers the engineering, the stations, and the project timeline. It also gives insights into the unfinished final 3.2 miles to Claremont and Montclair, which remain the defining funding and schedule question.
| Segment | Length and Stations | Funding and Clearance Basis | Status (2026) |
|---|---|---|---|
| Phase 2A: Sierra Madre Villa to APU/Citrus | 11.5 miles; 6 stations (Arcadia, Monrovia, Duarte/City of Hope, Irwindale, Azusa Downtown, APU/Citrus College) | Measure R; CEQA Final EIR; roughly $741 million | Open since March 5, 2016 |
| Phase 2B: APU/Citrus to Pomona | 9.1 miles; 4 new stations (Glendora, San Dimas, La Verne/Fairplex, Pomona North) | Measure M and Measure R plus state grants; approximately $1.5 billion | Open since September 19, 2025 |
| Pomona to Claremont (Los Angeles County) | Western portion of the 3.2-mile Pomona-Montclair segment; 1 station (Claremont) | 2013 Final EIR (SCH No. 2010121069) as amended by Supplemental EIRs; about $798 million in state-sourced Metro allocations (SB 125 funding) | Pre-construction; funded |
| Claremont to Montclair (San Bernardino County) | Eastern end of the same segment, crossing the county line; 1 terminal station (Montclair) | $41 million 2018 TIRCP award; remaining gap requires San Bernardino County and SBCTA participation | Funding gap after over-budget bids |
Engineering and Right-of-Way
The extension follows the former Atchison, Topeka and Santa Fe Pasadena Subdivision, a corridor that Los Angeles County acquired in 1992 for rail transit use. The alignment is predominantly at-grade within that preserved corridor, with grade separations reserved for arterial crossings where traffic volumes made gate-down times unacceptable. Environmental clearance for the entire 12.3-mile Azusa-to-Montclair Phase 2B was established by a 2013 Final Environmental Impact Report under the California Environmental Quality Act, followed by Supplemental EIRs that addressed phasing changes and station design revisions.
Crossing Protection and Signaling
- Grade crossings: Warning devices and gate configurations are subject to California Public Utilities Commission review under General Order 75-D, with the CPUC's Rail Crossings Engineering section approving each crossing's design.
- Safety oversight: The CPUC also serves as the State Safety Oversight agency for LA Metro under General Order 164-E.
- Signal priority: Wayside block signaling operates alongside traffic-signal preemption at street crossings, a design that the Gold Line has used since its 2003 opening.
- Freeway interfaces: Work inside Los Angeles County falls under Caltrans District 7. The Montclair terminus lies in San Bernardino County, which is Caltrans District 8, so the last station crosses an institutional boundary as well as a county line.
Operations, Fleet, and Connectivity
Since the Regional Connector entered service in June 2023, the A Line has operated as a continuous Long Beach-to-Azusa route, and the Pomona extension lengthens that run to well over 55 miles of through-service. Metro's operating plan assumed approximately 10-minute peak headways with 12 to 20 minutes off-peak, so riders should confirm current frequencies in Metro's published timetables.
- Rolling stock: The line draws on the Kinki Sharyo P3010 and Breda A650 fleets, while CRRC HR4000 vehicles are entering the Metro light-rail fleet through the 2020s.
- Metrolink (SCAX) transfer: Pomona North Station adjoins the Metrolink San Bernardino Line, creating a short transfer to Los Angeles Union Station. Claremont and Montclair would extend that pattern, since both cities already have Metrolink stations.
- High-speed rail context: The California High-Speed Rail Authority (CHSRA) plans its Southern California terminus at Los Angeles Union Station, which the A Line already reaches through the Regional Connector.
Funding Mechanics and Project Timeline
Measure R (2008, one-half-cent sales tax, 30 years) financed Phase 2A and early Phase 2B work. Measure M (2016, one-half-cent, passed with roughly 71 percent) added the dedicated Foothill Gold Line expenditure line. Unlike many Metro rail projects, the extension was not built around an FTA Capital Investment Grants Full Funding Grant Agreement, so there is no federal Record of Decision driving its schedule. The pacing instruments are Measure M's expenditure plan, state programs such as TIRCP, and Construction Authority contract awards.
- 2013: Final EIR certified for Azusa to Montclair.
- 2016: Phase 2A opens to APU/Citrus College.
- January 2025: Substantial completion of the Pomona segment, followed by Metro pre-revenue testing.
- September 19, 2025: Revenue service begins at Glendora, San Dimas, La Verne/Fairplex, and Pomona North.
- 2026 onward: Pomona-to-Claremont design and procurement continue, and the Montclair segment awaits a closed funding plan. Check current Construction Authority and Metro Board packets for dated milestones before relying on any opening estimate.
Historical Continuity with Pacific Electric
The foothill communities were first connected to Los Angeles by Pacific Electric Red Cars, whose Monrovia-Glendora and San Bernardino lines served the same communities from the early 1900s. Mid-century abandonment left the region dependent on freeways and the Santa Fe freight corridor until Metro reactivated it for light rail. The A Line therefore restores a transit relationship that Henry Huntington's interurban network established, at modern capacity and with grade-separated safety standards.