Alameda Corridor Mid


The centerpiece of the Alameda Corridor is the Mid-Corridor Trench, which is 10 miles long, 33 feet deep and 51 feet wide.  Traveling north from the Ports, cargo-laden trains descend into the trench north of State Route 91 in Compton and emerge at 25th Street near the border of Vernon and Los Angeles.  Not only does it link the North and South Ends of the Corridor, but it also includes most of the new signalized trackwork throughout the entire Corridor. The Mid-Corridor Trench represents about two-thirds of the expenditures of the Alameda Corridor. The 10-mile long trench contains three mainlines with a total of 30-miles of track to handle long-term growth in cargo volumes to and from the Port complexes of Los Angeles and Long Beach.

The 10-mile-long trench follows Alameda Street through six independent Cities and provides improved aesthetics, noise mitigation and traffic flow. Bridges carry vehicles over the Mid-Corridor Trench at 30 east-west crossings, completely separating rail traffic from street traffic and significantly reducing congestion.  The trench walls consist of 3′ diameter piles, braced at the bottom by a concrete slab and at the top by precast concrete struts. Over 1 million cubic yards of concrete and 75,000 tons of reinforcing steel were used, and 400,000 tons of ballast were placed to support the tracks. Nearly twenty miles of adjacent roadway were also reconstructed and the signals synchronized to further improve traffic flow. Nearly 60 miles of tracks were constructed throughout the Corridor, 30 miles of which are in the Trench.

Project details can be found below.  A map depicting this project can also be viewed here.


  • More efficient freight rail movements
  • Reduced traffic congestion by eliminating at-grade crossings
  • Improvements to the adjacent Alameda Street
  • Multiple community beautification projects
  • Less train emissions
  • Eliminated vehicle delays and emissions at railroad crossings
  • Less train noise
  • Train capacity to meet long-term cargo forecast

Community Benefits

Through its contractors and various community partnerships, ACTA administered several programs during construction designed to provide local residents and businesses with direct benefits that will long outlive actual construction.

  • Construction industry-specific job training for 1,281 local residents, including 637 placed in union apprenticeships.
  • 30% of all labor hours for Mid-Corridor Trench were performed by local residents living in adjacent zip codes
  • Through aggressive outreach and technical assistance, ACTA helped disadvantaged (primarily small and woman- or minority-owned) businesses compete for and earn contracts worth more than $285 million, meeting the program goal of 22 percent of all contracts.
  • On-the-job training and education credits for more than 420 young adults (ages 18-23), who performed community beautification work through the Conservation Corps program.
  • One-on-one technical consulting for 25 local import-export companies and entry-level, international trade-specific job training for 20 local residents through a joint program with the World Trade Center Association Los Angeles-Long Beach.

Construction Period

January 1999 to October 2001



Designer / Builder

Tutor Saliba/Parson Transportation Group/HNTB Joint Venture


Alameda Corridor Engineering Team

Historical Note

The Mid-Corridor section is of exceptional historical note as it has always been the preferred trade route reaching back to the discovery and founding of the City of Los Angeles. When Portuguese explorer Juan Rodriguez Cabrillo first sighted the Los Angeles coast in 1542, the local Native American tribe the, “Yang-Na” had been using the Alameda Corridor strip, an abandoned river wash, to travel between the downtown Los Angeles area to the Wilmington area to trade with the Native Americans living on Catalina Island.

As the population in the Pueblo Los Angeles began to grow, a trade route along the Alameda Corridor began to further take shape. As an already proven direct path to the Port in San Pedro, the route became preferred by traders moving goods back and forth as well as stage coach travelers.

In 1869, Phineas Banning dedicated the Los Angeles & San Pedro Railroad to move an even greater influx of freight into Los Angeles.  The rail line was used as an incentive to convince the major railroads to connect Los Angeles to the transcontinental rail system. The Los Angeles & San Pedro Railroad was sold to the Southern Pacific Railroad in 1873.

The Mid-Corridor section continues to be a part of the original Goods Movement concept that dates back to the development of the Southern California region.