The Challenges of Positive Train Control


by Lawrence Light, Director of PTC via Mass Transit

One of the most sought after safety systems, Positive Train Control, has been on the National Transportations Board’s “Most Wanted List” for many years. Yet, despite nearly seven years of anticipation for FRA’s PTC deadline and nearly 20 years of awareness of system requirements, most carriers will not have a PTC system by Dec. 31. With more than 40 railroads filing for installation of PTC under the mandate, few will have PTC in revenue service on time. Four principal factors impacting timely completion are:

1. Complexity of the chosen architecture

2. Individual railroad’s safety philosophies

3. Availability of multiple vendors

4. Development time available, given 1, 2 & 3 above

These four factors are best illustrated by visiting brief histories of four very different PTC technologies seeking certification as FRA Type-Approved (TA) PTC.

ATC/ACSES had a significant head start on the other three systems, beginning in 1993 with the goal of 150mph for high speed trains in the Northeast Corridor. With the simplest architecture, a unique blend of domestic ATC and European transponders following FRA’s established safety Rules, Standards & Instructions for Signals (The RS&I) and with availability from multiple vendors, Amtrak has received final FRA TA certification and expects to meet the deadline for its lines in the Northeast. However, due to a later start, other agencies in the Northeast with lines adjacent to Amtrak will not meet the deadline.

ITCS, was first conceived in 1995 with the original goal of breaking the 79 mph barrier, and with multiple improvements in service, 2000 – 2012, Amtrak began 110 mph operation in February 2012 and received final FRA TAPTC certification in December 2012. ITCS is RS&I compliant with simpler architecture than I-ETMS, and has an important highway crossing warning advance start feature saving millions upon deployment in the emerging corridors with many road crossings. ITCS has one vendor, but thanks to an early start, Amtrak-owned lines in Michigan and Indiana will meet the deadline.

I-ETMS, is a blend of BNSF’s ETMS and UPRR’s V-ETMS, which when merged as I-ETMS appears to have strayed from the goal of vitality. This has led to recent FRA challenges regarding many safety concerns. Unfortunately, pursuit of corollary benefits has created an architectural complexity resulting in a costly increase in overall completion time. Of all the railroads seeking to deploy I-ETMS, only Southern California’s Metrolink expects to be PTC ready by the deadline. Currently, there is only one vendor available to supply the needs of many railroads.

E-ATC, an extension of the ATC concept, is the simplest of all the systems in architecture and safety philosophy (RS&I Compliant); can be supplied by multiple vendors, and can be developed relatively quickly for new PTC initiatives. And while at least two PTC initiatives are able to eliminate data radio and transponders, this is not always possible without losing needed operational utility.

In conclusion, the combination of later deployment of I-ETMS and a lack of consideration for the “four factors” has resulted in the need for additional implementation time. With the majority of carriers filing to install PTC committed to the I-ETMS technology, this has caused much anxiety for a large segment of the industry not meeting the deadline, and with the lack of multiple vendors, budgets are being strained to the breaking point. If granted, a congressional extension of the deadline could provide time for some operators to consider simpler, more mature and less costly alternatives.