Human Systems Integration Division @ NASA Ames

The Rail Safety Improvement Act of 2008 (RSIA) mandated the implementation of Positive Train Control (PTC) systems on Class I railroads’ main lines, which consist of over five million gross tons of annual traffic, transportation of certain hazardous materials, and intercity/commuter rail passenger transportation. After two extensions by Congress, full implementation was required by December 31, 2020. PTC technology is designed to prevent:

- Train-to-Train Collisions

- Over-Speed Derailments

- Incursions into Established Work Zones

- Movements of Trains through Switches Left in the Wrong Position

The purpose of this Confidential Close Call Reporting System (C3RS) study was to learn about the potential operational risks associated with PTC focusing on the integration and operation of PTC systems. Studying the reported C3RS close-call events regarding PTC was expected to yield information about the risks that may be present in the operation of PTC systems. Generally, this research set out to accomplish three things:

- Demonstrate the usefulness of C3RS data analyses

- Define a process for determining safety issues derived from data

- Outline specific strategies to identify and help mitigate operational risks of PTC