Oakland Wye
| Company type | Infrastructure junction |
|---|---|
| Industry | Public transportation |
| Founded | 1986 |
| Headquarters | Oakland, California , United States |
| Products | Rail junction for Bay Area Rapid Transit (BART) |
The Oakland Wye is a subterranean flying wye junction located in the heart of Oakland, California, integral to the Bay Area Rapid Transit (BART) network. It links three principal routes: (a) the northbound Richmond or Antioch lines (originating at , underground), (b) the westbound San Francisco lines (beginning at , elevated), and (c) the southbound Berryessa or Dublin/Pleasanton lines (starting at , underground). Serving as the focal point of the BART system, all rail mileage markers are measured from this junction, making it a vital chokepoint since almost every scheduled BART train traverses it, with the exceptions of the Oakland Airport Connector and eBART services.
Design
Positioned beneath Broadway and 9th Streets, the wye functions as a flying junction. Trains arriving from approach via tunnels under Broadway, those from travel beneath 9th Street, while elevated trains from enter subterranean tunnels near Washington and 5th Streets before curving toward Broadway. A supplementary third track, known as MX/CX, runs between West Oakland and 12th Street stations to boost capacity and is commonly utilized by -bound trains. Emergency exits are situated at intersections of 7th & Broadway and 9th & Harrison.
Although initially engineered for speeds reaching , operational constraints necessitated lowering speed limits to on most tracks as a safety measure. The central "CX" track permits trains to maintain speeds up to through the Wye.
Construction
Original designs placed the Wye beneath Broadway and 8th Street; however, this was later relocated to Broadway and 9th Street. This adjustment resulted in a sharper curve between Lake Merritt and 12th Street/Oakland City Center stations, consequently reducing allowable speeds. Historical accounts indicate that then-Oakland mayor John C. Houlihan played a role in this alteration due to political motivations.
Completed in 1986, a third track (MX/CX) connects West Oakland, 12th Street Oakland City Center, , and stations. Initially deployed during peak periods (westbound mornings and eastbound evenings), since 1992 it has predominantly served eastbound Yellow Line trains, enabling convenient cross-platform transfers with Orange Line services.
Incidents
On December 17, 1992, a southbound train mistakenly ran on the northbound track for maintenance reasons and caused a switch to split at the Wye’s northern end, resulting in injuries to 14 passengers.
In February 2000, an unsecured cable led to failures in automatic train control systems, requiring trains passing through the Wye to be operated manually at reduced speeds between 5 and 10 mph during track switching.
In February 2009, a collision occurred when two northbound trains from West Oakland and Lake Merritt merged toward 12th Street/Oakland City Center within the Wye; one of these trains was under manual operation. The impact caused partial derailment.
Future
Plans have been proposed to establish a direct connection between MacArthur and Oakland Coliseum stations via the Transbay Tube. This initiative aims to provide express service options, alleviate systemwide delays caused by congestion in the Oakland Wye, and possibly introduce an infill station at Jack London Square. Constructing a turnback within the Oakland Wye could facilitate additional infill stations or higher service frequencies in core urban areas, thereby enhancing capacity and operational adaptability.