San Diego is taking early steps toward what could become one of the region’s most ambitious public transit projects.
Regional planners are beginning to study a proposed high-capacity metro line known as the Purple Line, a north–south corridor that could significantly change how residents travel across the county.
The proposed route would connect San Ysidro near the U.S.–Mexico border to Sorrento Mesa, with stops in communities such as Chula Vista, National City, City Heights, and Kearny Mesa. The line is envisioned as a fast, frequent transit option linking residential areas with major employment centers.
According to the San Diego Association of Governments (SANDAG), the region’s transportation planning agency, the Purple Line is intended to deliver reliable, high-frequency service for underserved communities while also offering a practical alternative to driving for commuters across the region. The project would integrate with the existing transit system, connecting with trolley lines, rapid bus routes, and major transit hubs.
Planners say the line could expand access to jobs, education, healthcare, and other essential services.
SANDAG recently completed an initial conceptual study examining whether the project could be built as a true metro system. No final decisions have been made, and there is currently no construction timeline. Future studies will explore different design options, including whether the line would operate as an elevated train, street-level rail, or another configuration.
Major rail projects of this scale typically take 15 to 20 years from planning through construction, according to regional transportation officials.
