Date: June 11, 2021
Author(s): Yu Hong Hwang
Abstract
Los Angeles County Metropolitan Transportation Authority (LA Metro) planning staff, working alongside engineers from the Los Angeles Department of Transportation (LADOT) seek to make improvements to the Metro G Line (Orange) busway to address a number of operational problems with the popular line. The Metro G Line is the backbone of transit in the San Fernando Valley, serving more than 22,000 pre-COVID-19 pandemic weekday boardings.
Part of the problem for public transit in a chronically traffic congested place like Los Angeles is that buses typically have to compete for road space with private automobiles. As a result, buses get stuck in traffic. Light rail vehicles, when travelling on surface streets with cars, get stuck in traffic as well. The G line busway thus has a significant advantage, as it runs on its own dedicated route. Efforts to further separate the G line from nearby traffic, such as grade separated over- and under-passes or railroad-style gate arms at street crossings, will require complex planning and take considerable time and resources to implement. However, speeding up the G line with current infrastructure is possible by improving transit signal priority (TSP). TSP prioritizes a direction along a roadway by extending green time at signals so priority vehicles (in this case buses) can pass through an intersection without stopping.
This report explores the current signal regime along the G line alignment, some of the history of the TSP system, and draws on case studies to develop applicable lessons to the Metro G line.
About the Project
Buses get stuck in traffic. Allowing priority at stoplights is one possible solution to speed them along. Transit signal priority in the City of Los Angeles faces a host of constraints. These are both technology and policy based, with the City Department of Transportation relying on transponder technology that must be keyed to individual buses and hesitant to introduce additional delays for private vehicles. LA Metro would like to pilot a program to loosen the schedule- and traffic signal cycle-based restrictions put in place by LADOT. The pilot, scheduled to occur along the A (Blue), E (Expo), G (Orange) light rail and BRT lines and 720 Wilshire and 754 Vermont bus lines, could speed many more riders along some of the busiest transit corridors in Los Angeles. By introducing smoother flows for transit vehicles in Los Angeles, it may spur transit adoption by offering more competitive travel times.