Washington Blvd and Flower St: The Intersection from Hell
Light rail in Los Angeles is, by most measures, a great success. The Blue Line is the second busiest LRT line in the United States with 80,000 daily riders, and the Green and Gold Lines together attract around 70,000 more riders. During peak periods, the Blue Line operates at a high frequency, with 12 trains per hour and is capacity limited by its numerous grade crossings and the stub terminal at 7th Street/Metro Center. With the upcoming opening of the Exposition Line, the capacity constraints of the Downtown portion of the Blue Line, which Expo will share, will become a pressing issue. The most pressing bottlenecks are the 7th/Metro Center terminal, which only has two tracks, and the Washington Boulevard and Flower Street intersection. After the opening of the Exposition Line, this intersection will truly become hellish.
Currently, the Washington/Flower intersection consists of Flower Street, a 3 lane one-way street, Washington Boulevard, a 6 lane arterial, and the Blue Line LRT tracks curving across part of the intersection. See the diagram for which lanes are impacted by LRT operations. After the installation of the Exposition Line, LRT tracks will also run through the intersection, continuing down Flower Street. This will affect several new directions of traffic and pose further hazards and danger to pedestrians, who are already banned from crossing the north side of the intersection. Critically, any change of signal timing due to a LRT delay, pedestrian crossing the street, or automobile incident (accident), will cause immediate gridlock for the 150,000 or more LRT passengers, 30,000 drivers and countless pedestrians who use this intersection.
Adding insult to injury, the California Public Utilities Commission has required the installation of a special signal system at this intersection, causing a further delay to the opening of the Exposition Line. Just yesterday, Washington Boulevard was closed for construction and I walked the site a bit. Rail has finally been installed for the Exposition Line, but much of the electrical equipment, including the overhead contact system (OCS) for LRT trains, has yet to be installed.
So, why write about this intersection from hell: to propose an alternative. Granted, it is far too late to make serious design changes in the Exposition Line, but in the future a huge change will be necessary: a massive grade separation structure. The mess of rail, road and pedestrian infrastructure at Washington/Flower, along with a nearby intersection with a far more heavily used arterial (Figueroa Street) make this situation nearly impossible to address using an underpass or overpass of the roadway. Rather, the best option remains raising or submerging the LRT tracks. Approximately half a mile north of this intersection, the LRT tracks enter subway on the way to the 7th Street/Metro Center Station.
Two alternatives for grade separation exist. The cheaper, easier method would be a large elevated separation structure over the intersection. Now, for maximum efficiency, a full flying junction of the Blue and Expo Lines would be required. That means this elevated separation structure could consist of three elevated levels, meaning there would be a 60-80 foot tall concrete structure over this intersection. Steep grades may be necessary for a return to grade level on the northern branch to 7th/Metro Center to get under the Santa Monica Freeway, so this option is not ideal.
Now, as in my last post, planning for the future and investing heavily in high capacity, high-quality rail transit infrastructure is my favorite outcome for any rail project. In this case, just like the connection between the Regional Connector and the Gold Line, an extended subway and flying junction underground separation structure would be ideal. Extending the subway south from 7th/Metro Center all the way to Washington Boulevard and Hill Street to the East and 21st Street to the South. Such an arrangement could increase capacity in this junction exponentially, and could also greatly improve the pedestrian environment south of Downtown Los Angeles.
But, what if this underground grade separation structure is not enough? The 2030 estimated ridership for both the Blue Line and the Expo Line is well over 120,00o riders each, meaning this junction could have to handle over 200,000 riders a day. That is more than BART’s Transbay Tube in Northern California, a facility that is widely considered at full capacity, and a facility that can accommodate 710-foot long heavy rail trains, not 270 foot long LRT trains. To handle this number of riders the combined Expo/Blue Line segment between this grade separation and the junction between the Regional Connector and Gold Line, would require 50-60 trains per hour, nearly a train every minute! No rail line on earth handles this many trains on two tracks, especially with switches on either end of the line.
All signs point to a dedicated second downtown subway for light rail in Los Angeles. Like the separated Blue Line idea in Washington DC, capacity constraints on a single downtown segment of the Expo and Blue lines will limit frequency on the outer branches. This phenomenon exists in San Francisco, where outer branches of the BART system are seriously underserved at times due to capacity constraints in the Transbay Tube and Market Street Subway. Metro needs to give this Expo/Blue Line problem a whole lot more th0ught before Los Angeles ends up with an operations and traffic nightmare.