PTC 2.0: Taking railroad safety beyond the original PTC

What is next in railroad safety?

As of December 29th, 2020, PTC (Positive Train Control) is operational on all required freight and passenger railroad route miles. The 41 railroads subject to the statutory mandate have worked for more than a decade to achieve this unprecedented landmark or what FRA Administrator Ronald L. Batory called “unprecedented undertaking” for almost 100 stakeholders, from freight and commuter railroads to suppliers and industry associations. Nevertheless, improving and optimizing railroad safety never ends and railroads are exploring the next steps to mitigate more safety hazards. LILEE Systems, a trusted PTC partner from the very beginning, has a vision and a product to make what some people call PTC 2.0, today.

From FRA’s vision to LILEE’s vision

From the beginning of this century, FRA had a vision of what a PTC system should include: “…. PTC systems issue movement authorities to train and maintenance-of-way crews, track the location of the trains and maintenance-of-way vehicles, have the ability to automatically enforce movement authorities, and continually update operating data systems with information on the location of trains, locomotives, cars, and crews….” (partial vision). Here at LILEE, we took this vision to our hearts and minds and developed the first maintenance-of-way safety system that provides Limits Compliance and Collision Avoidance for MOW vehicles on the tracks and the road.

Vehicle position accuracy:

The solution integrates the newest technologies that were not available 20 years ago. For example, many railroads are looking into implementing PSR (Precision Scheduled Railroading) and the knowledge of the exact location of the train is essential, even when there are tunnels and bridges and other obstacles in the way, for efficient handling of en-route failures. GPS has been available for a very long time but using only GPS results in too many dead spots. While many workarounds were developed in the past, they did not help much with the railroad’s specific use cases. These fail-safe systems simply yet falsely stop the train after too many dead zones are encountered. GNSS (Global Navigation Satellite System) with Galileo, which is a global system, operated and owned by the European Union (EU), is newly approved by the FCC (Federal Communications Commission) to be used for critical infrastructure, including U.S. railroads, to provide PNT (Position Navigation Timing). GNSS adds accuracy, redundancy and availability at all times when combined with RTK (Real Time Kinematics), IMU and track map using sensor fusion technology. The current technology enables the system to perform track discrimination with a confidence level exceeding 99.9%, which allows onboard and back-office systems to know what track a vehicle is on and eliminate the human error from requiring the driver to manually enter the track ID.

Vehicle collision avoidance and roadway worker protection:

For MOW vehicles and roadway workers, the FRA’s vision for PTC has not been achieved yet. LILEE’s vision is now achieved with its latest product that closely follows what FRA envisioned: to reliably detect and warn about incursions into the established work zone and to allow roadway workers to electronically communicate train speed movement authority. If communication is not available between the train and the roadway workers, messages are relayed through the dispatcher who can then send the electronic message and provide roadway workers with speed and authorization to move.

Roadway workers can still unknowingly deploy on-track equipment on unauthorized tracks, sometimes resulting in catastrophic consequences. With the integration with the PTC dispatch system, GNSS receivers, RTK adjustments and IMU sensor fusion, it is now possible to reliably determine if that on-track equipment is deployed in the correct track, and alerts and warnings are sent when the wrong track is detected. Cab displays are used on MOW vehicles to provide the location of the other MOW vehicles and trains in the work zone. If two MOW vehicles in the work zone come too close to each other, proximity alerts are generated to warn the driver about the potentially unsafe situation.

Besides, while PTC is designed to prevent an unauthorized train from entering a work zone, it does not prevent MOW vehicles from leaving their work zone limits. The onboard Cab display can also provide audio and visual authority limits alerts to warn the driver if the MOW vehicle is getting too close to the work zone limits. Furthermore, work zone speed limit compliance is constantly monitored to ensure the safety of both the driver and the roadway workers.

AI-based object detection for collision avoidance using the latest sensor technology combining cameras, radar and LiDAR further provides an additional layer of safety. It can detect other MOW vehicles in the way and send alerts when it is getting too close. For roadway workers, it is also unsafe to work in close vicinity to heavy on-track equipment. The AI-based collision avoidance system on the equipment can recognize and detect the roadway workers and provide alerts to the operator to temporarily stop its on-track movement.

Grade crossing collision avoidance: 

With today’s technology, we shall be able to go beyond train-to-train collision avoidance and provide train-to-vehicle collision avoidance. That will be greatly improve railroad safety at grade crossings. Wireless grade crossing implementations lead to fewer accidents and improved reliability. Still, more than 60% of grade crossing accidents happen at the wireless grade crossings even with active warning devices and 90% of the accidents are due to human error. Moreover, stalled cars on the track account for one of the top ten causes of train accidents, and trespassing pedestrians are responsible for more railroad-related deaths than the combined total of derailments and other train accidents. Such accidents and deaths can be prevented with the current technology that has been developed for autonomous driving during the past five years.
Level-5 autonomous driving may still be many years away, but the rail industry can mitigate the wireless grade crossing accidents through the AI-based object detection technology for autonomous driving. From a railway’s perspective, the object detection system can be installed and integrated with crossing WIU (Wayside Interface Unit) at the grade crossing to establish a safety zone (or virtual fence). If an object in the safety zone is detected, a message is sent to the approaching locomotive and the train can be stopped safely before the crossing. Unlike the traditional camera-only-based object detection design, the combination of cameras, radar and LiDAR sensors paired with AI-based sensor fusion technology provides much higher accuracy and reliability in object detection capabilities even under adverse weather conditions.

Ready for the next step?

The railroad industry has completed the very complex and as such, also very expensive PTC. Now is the time to plan and implement PTC 2.0, the second phase of the railroad safety system that FRA envisioned so many years ago to further protect MOW crews and assets.

Schedule a call to discuss the PTC 2.0 solution with LILEE’s rail safety expert Yale Lee at

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About the Author

Yale Lee
Yale Lee is the Co-founder and Vice President of Technology at LILEE Systems. He has over twenty years of product development experience in the networking and security industry. Yale has led the LILEE engineering and professional services teams to develop and deliver wireless communications solutions to North American Class I railroads to meet Positive Train Control (PTC) requirements.
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