The long‑planned D (Purple) Line Extension is transforming mobility along Los Angeles’ congested Wilshire corridor. First envisioned more than 50 years ago as a key connection between downtown Los Angeles and Westwood, this major transit investment is bringing new high‑capacity rail service to one of the region’s busiest travel corridors. As part of the Tutor Perini and O&G Industries design‑build team, STV serves as engineer‑of‑record and principal designer for the 2.59‑mile Section 2 extension linking Metro’s Section 1 in the Miracle Mile District with Section 3 connecting Century City to Westwood. This work supports Metro’s broader $9.3 billion program to extend the Purple Line 9.1 miles from Koreatown to Westwood.
What challenges is STV addressing?
The project aims to reduce congestion in one of Los Angeles’ most heavily traveled corridors and improve mobility between major residential, commercial and employment centers. Addressing complex underground conditions, dense urban environments and maintaining community access are central challenges as the extension advances beneath Beverly Hills and Century City.
What solutions is STV delivering?
STV is designing the Wilshire/Rodeo and Century City/Constellation stations along with the twin running tunnels. The firm engineered the Century City launch box that enabled the lowering of two 400‑foot‑long TBMs into excavations more than 70 feet below Constellation Boulevard for a 14‑month tunneling drive. In addition to leading design for Section 2, STV serves as lead designer and systems integrator for the adjacent 2.56‑mile Section 3 extension.
How will this project benefit the region?
The extension will strengthen regional mobility and support access to one of Los Angeles County’s largest job hubs in Century City. It will connect communities with reliable, high‑capacity rail service that reduces automobile dependence and supports long‑term economic growth. New stations will offer residents, commuters and visitors faster connections to key activity centers throughout Los Angeles.
Key stats and accolades
- 2.59 miles of new transit infrastructure
- 400‑foot‑long tunnel boring machines
- Tunnel excavations extending more than 70 feet below grade
