InMotion_Summer 2025

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upgraded PSDs, these agencies have achieved significant benefits such as cleaner and quieter platforms, less debris on tracks, reduced energy consumption due to loss of HVAC in tunnels, and enhanced passenger information, entertainment, lighting and advertising. PSD implementations offer significant benefits for the riders, but they also come with several challenges. Consideration must be given to areas such as interface requirements with other subsystems, grounding methods to mitigate potential shock hazards, impact on subway operations, and construction phasing. Major agencies including BART, the Toronto Transit Commission (TTC), NYCT and others have looked to Lea+Elliott to support their PSD efforts via planning, feasibility studies, cost estimates, and preliminary design activities. We have also investigated and reported on alternative technologies that provide platform edge protection at a lower cost point with less required civil/structural station work. Lea+Elliott engineers have worked with automated transit systems that use platform doors since the early days of APM systems. Our staff has a wealth of expertise and compiled lessons learned from our PSD integration work. As transit agencies throughout North America continue to upgrade their train control systems and consider passenger safety enhancements such as Platform Screen Door systems, we look forward to supporting those initiatives with the technical expertise built from decades of implementing automated transit systems. For additional information about the services that we provide to rail transit systems, please visit www.leaelliott.com.

in CBTC products, as well as other emerging technologies. CBTC has been in use on APM systems for decades, with Lea+Elliott positioned as a recognized authority in the planning, procurement, and implementation oversight for such systems. Migration to CBTC Technology Rail and metro properties throughout Europe and Asia have been deploying CBTC technology over the past 10-20 years, and transit owners in the United States have recently started to follow suit. Transit agencies in the U.S. have been reliant on the broken rail detection function that is inherent with fixed block technology. However, the broken rail detection functionality of track circuits cannot detect minor cracks and fissures that eventually lead to catastrophic rail failure. New technology like ultrasonic monitors can scan rails and detect when the integrity of the rail is starting to degrade. This allows for preventative rather than reactionary maintenance. The advent of new technologies, the substantial benefits offered by a CBTC upgrade, and the continued aging of legacy train control systems have all led to growing interest in CBTC. Bay Area Rapid Transit (BART) and New York City Transit (NYCT) are two of the largest transit systems in the U.S. and both have recently begun upgrading to CBTC. Now that those agencies have paved the way, others including WMATA, MARTA and SEPTA are following. Lea+Elliott’s CBTC engineers now assist many agencies in making a smooth and efficient transition to CBTC. Platform Door Trends The roll out of Platform Screen Doors (PSDs) has followed a similar trajectory to the introduction of CBTC on transit systems around the world. Ten to 20 years ago, agencies in Europe and Asia made a major push to achieve the higher level of safety and security provided through the retrofit of PSDs. Since installing

Platform Screen Doors on the Hartsfield-Jackson Atlanta International Airport’s ATL SkyTrain system

In Motion

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