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InTransition Magazine : Transportation Planning, Practice & Progress

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Research News from NJIT

Analysis Proposes Allowing Commuter and Light Rail Vehicles to Share Tracks

New Jersey Institute of Technology (NJIT) researchers recently completed a white paper advocating that federal rail safety regulations prohibiting commuter and light rail vehicles from sharing the same tracks be altered. In the paper, titled “Shared Service: Mixing Commuter and Light Rail in New Jersey,” the authors contend, “This segregation makes U.S. rail comparatively expensive and its inefficiency negates the energy savings that makes rail sustainable.”

The authors propose a new form of transit service that could be implemented if the federal regulations could be waived. The concept, “Expanded Light Rail (XLR),” involves running light rail vehicles on commuter rail tracks that would otherwise go unused in order to increase capacity and utilize these assets more efficiently.

Radical changes in transportation patterns and preferences are on the horizon, the paper contends. “Transit will be to the 21st century what the automobile was to the 20th,” according to the authors, and while other countries around the world have embraced this “new normal,” some U.S. regulations are stuck in the past.

One regulation cited as a hindrance to the development of rail transit in the U.S. is the Passenger Equipment Safety Standards (PESS). The purpose of the PESS is to protect passengers in the event of a collision by requiring stronger vehicles that can withstand a crash, an approach referred to as “passive safety.” Rail safety standards in Europe pursue “active safety” enhancements, which work to prevent collisions. For example, Positive Train Control (PTC) systems, utilized on European rail networks, track a train’s movements and can automatically apply the brakes if the train is on an unsafe course. These systems allow light, commuter and freight rail vehicles to safely use the same section of track.

However, U.S. safety standards essentially mandate “that if vehicles cannot be physically armored to sustain impact, heavy and light rail must be temporally separated,” regardless of any other safety features. The authors refer to this policy as the “strength incompatibility” doctrine and summarized its unintended consequences in four categories:

Availability of Equipment: Most U.S. operators buy vehicles from European manufacturers that mainly build trains to satisfy EU regulations. Vehicles built to U.S. standards are typically custom orders that cost 25 percent more.
Service Limitations: Only one U.S. manufacturer has developed a vehicle that satisfies the PESS and is allowed to operate on both light rail and commuter rail tracks. It is expensive and heavy because of the additional armor required by law. None have been bought by any U.S. transit authority to be used for mass transit.
Cost Efficiency: Compliance with the PESS effectively increases capital and operating costs. Excessive weight makes the vehicles less
fuel-efficient. Tracks are not fully utilized. As a result of these inefficiencies, many rail lines have been abandoned and the rights of way lost to development.
Sustainability: Quality urban mass transit encourages higher density development, which is greener than sprawl, but the PESS makes that harder to achieve.

The 2008 Rail Safety Improvement Act, has required the Federal Transit Administration to implement PTC systems on certain rail lines by 2015. The authors claim that these additional “active safety” improvements will render the PESS redundant. Now, if the Federal Railroad Administration (FRA) can be convinced to waive the restrictions, tremendous service increases at minimal cost could ensue, and the inefficiencies and resulting consequences described above could be eliminated.

Mixed operations of PTC-enabled light and commuter rail vehicles have been proven safe, and indications are “that the FRA may be inclined to support a serious effort to achieve this,” the authors note. “The mandate to deploy PTC combined with a federal administration eager to seek sustainable efforts to leverage transportation and land use make this an auspicious time to petition the FRA.”

—Study Authors: Stelian Canjea, James C. Greller and Darius Sollohub, with Nhat Minh Bui

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