Positive Train Control (PTC) versus Enhanced Train Control (ETC)
Positive Train Control (PTC) is an automatic train protection system in the US that prevents train collisions and derailments caused by excessive speed. Canada’s equivalent of PTC is Enhanced Train Control (ETC), which aims to eliminate catastrophic train-to-train collisions, train overspeed derailments, and train derailments caused by misaligned track switches, all due to “human error.”
The implementation deadline of ETC in Canada is 2030.
Safety Levels of ETC
The Canadian Rail Research Laboratory (CaRRL) of the University of Alberta was contracted by Transport Canada to perform an in-depth investigation into the potential safety benefits gained from the introduction of ETC technology to the Canadian railway environment.
The CaRRL proposed four different levels of ETC functionality:
- Level 1 and Level 2 are Driver Advisory Systems (DAS).
- Level 3 and Level 4 are true “train control” solutions providing ATP functionality.
Specifically, Level 3 of the ETC system is intended to closely parallel the PTC system. It further increases in complexity by including, amongst other features, full buildouts into the wayside and positive enforcement of operating authorities. The implementation of Level 3 ETC requires interoperability with other ETC systems and technologies, which may be difficult given the diversity and complexity of the Canadian railway environment.
On the other hand, Level 1 of ETC is a crew assist and monitoring system that is minimally invasive and locomotive centric (i.e., no buildout into the wayside). It merely provides train crews with information about the train’s speed, location, and other relevant data, and alerts the crew of speed restrictions, upcoming signals, and other track conditions. ETC Level 2 improves the safety upon Level 1 by including an enforcement system that incorporates an interface with the train braking system (allowing the system to stop a train instead of only issuing warnings) and selective buildouts into the wayside through the monitoring of key switches.
To assess the effectiveness of ETC across different levels, we can use Movement Exceeds Limits of Authority (MELA) type occurrences as a metrics. The specific breakdown in preventability by ETC Level considering 1,168 MELA-type occurrences between 2007 and 2016 is:
- Level 1 ETC system: 463 occurrences or 37%
- Level 3 ETC system: 527 occurrences or 45%
- Level 4 ETC system: 682 occurrences or 58%
- Not ETC preventable: 486 occurrences or 42%
(No preventability is shown for the Level 2 ETC system as it is an intermediary between Levels 1 and 3 and incremental preventability will depend on the switches monitored.)
As shown above, Level-1 ETC prevented 463 out of the 527 occurrences addressed by Level-3 ETC, representing a substantial 88% of the protection offered by Level-3 ETC without the need for costly wayside infrastructure investment. Railroads should prioritize adopting Level-1 ETC even when not yet mandated. It adds an important layer of safety and results in significant cost savings by preventing accidents.
Implementing ETC: Solutions and Lessons Learned from PTC
Since 2009, LILEE Systems has played a significant role in enabling PTC systems for freight, passenger, and commuter rail systems. Class I Canadian railroads operating in the US have collaborating with LILEE to successfully implement PTC by the 2020 deadline and meeting federal requirements for system interoperability, compatibility, and wireless communications security. LILEE’s complete rail safety portfolio include:
- Train control solutions, including wayside messaging servers, wayside status relay service, PTC systems management gateway, ITCM-related development services, and ITCM network design, which have all been field tested for PTC systems following FRA-approved specifications.
- LILEE’s SafeRail™ solution for the DAS requirements of Level-1 ETC, offering an onboard Visual Display Unit (VDU) to provide real-time train speed, train location, and an optimal speed profile as well as alerts
- LILEE’s SafeRail™ integration with dispatch/PTC (ETC) system in the back office to streamline limits compliance and collision avoidance protection, which is essential to prevent train-to-vehicle collisions from human error
- LILEE’s SafeRail™ solution for ETC Level 2 functionality, integrating the vehicle braking system to allow the system to stop a vehicle instead of only issuing warnings
In sum, as Canada progresses towards the ETC implementation deadline of 2030, LILEE Systems stands as a trusted partner with its extensive industry experience and validated solutions in enabling PTC systems. Our proven track record with Class I Canadian and American railroads showcases our commitment to delivering rail safety solutions that are interoperable, secure, reliable and scalable.
Contact us today to speak directly with one of our PTC experts and discuss how to accelerate your ETC adoption.
