Billed as one of the largest construction projects ever undertaken within the city at a cost of $312.8 million, the San Gabriel trench welcomed its first train service on July 24 at a media ceremony held on the Mission Road bridge. While full train service from Union Pacific Railroad and Amtrak has yet to begin, the trench’s inaugural train signals the nearing completion of a five-year project that sought to mitigate the impact of rail line traffic on the community.

At 30 feet deep and 65 feet wide, the 1.4-mile San Gabriel trench project is massive in scope, featuring the excavation of over 500,000 cubic yards of soil, the use of over 33,000 dump trucks and 6,500 concrete trucks to complete the project. With these resources, ACE – or the Alameda Corridor-East Construction Authority – was able to construct a trench that could relocate rail traffic at four busy intersections. With railway tracks relocated below-grade in the trench, construction crews also constructed four bridges at Ramona Street, Mission Road, Del Mar Avenue and San Gabriel Boulevard to ensure a constant flow of motorists and pedestrians over railway traffic.

With the completion of all four bridges and the trench structure, construction crews are now waiting for Union Pacific Railroad officials to install new mainline tracks inside the trench. Once installed, construction crews will then remove the railroad shoofly – or temporary track – that currently lies adjacent to the trench, thereby eliminating railroad crossings at four intersections within the city. Work on the mainline track was originally scheduled to begin earlier this year, though severe rainfall and weather conditions in the state forced Union Pacific to refocus their work elsewhere to address service interruptions to their rail network.

Once completed, the San Gabriel trench will reduce congestion at four crossings by nearly 90,000 motorists, improve rail reliability for an average of 18 trains per day, eliminate noise caused by locomotive horns and crossing bells and reduce pollution caused by idling cars and trucks. More importantly, the new trench will also improve safety by eliminating delays for emergency responders at railway crossing points.

ACE expects that full rail service in the trench will begin in the coming weeks once Union Pacific completes the installation of new mainline tracks.