Working out the kinks
of positive train control

With the latest US Congressional deadline for positive train control implementation approaching, Amtrak may suspend services lacking the safety technology by the end of the year. joe baker uncovers exactly what goes into the successful installation and operation of this crucial technology

The implementation of positive train control (PTC) has been an ongoing battle for the US rail industry. While the computer-based system designed to automatically slow or stop speeding trains to prevent accidents seems straightforward, rolling it out is, unsurprisingly, complex.

In December 2017, the National Transportation Safety Board revealed that rail crashes that could have been prevented by PTC have led to 298 deaths, 6,763 injuries and nearly $385m in property damage since 1969, when the organisation first urged US railroads to adopt the technology.  

Then in 2008, after a Metrolink train crash killed 25 passengers in Los Angeles, US Congress enacted the Rail Safety Improvement Act of 2008, which required railroads to install PTC on all main-line tracks before December 2015. However, when it became apparent that many railroads would be unable to meet the deadline, it was extended to 2018.

Preventable rail disasters have continued in the meantime. US rail operator Amtrak has experienced several fatal train accidents in the past few months, and the media has cast a spotlight on the lack of PTC as a primary cause.  

Data from the Federal Railroad Administration (FRA) shows that, at the end of 2017, PTC systems were in operation across approximately 56% of freight railroads governed by the congressional mandate. But passenger railroads have made less progress, with PTC operational on only 24% of required routes.

At the end of February, the US Government Accountability Office (GAO) released its analysis of 41 railroads, including 29 commuter lines required to implement PTC, which revealed that as many as two thirds of the 29 commuter routes may not meet revised the deadline for the end of the year.

For US federal safety investigators, the question is not whether PTC is an urgent investment, but how soon it can be effectively operating across the country. However, funding and technical challenges have made this a Herculean task. 

PTC installation across the US is expected to cost up to $22.5bn

The complexities of PTC

Positive train control is a multi-faceted system incorporating GPS technology, trackside signals and digital radios connected to rail line dispatch centres.

In addition to equipment fitted on locomotives by rail operators, trackside systems must be installed by railroads to monitor signals switches and track circuits. These are linked by back office servers (BOS), which store millions of rail network data points – such as speed limits and layouts – and authorise trains to move onto the next segment of track.

PTC is, therefore, a system that touches the whole network and the deployment figures are staggering. The Association of American Railroads reports that Class 1 railroads in the US will be required to have PTC technology installed on more than 17,000 locomotives and install more than 24,000 wayside interface units across 54,000 miles of track. This is in addition to the development of BOS and dispatching software to incorporate the data and precision required for PTC systems.

With PTC installation across the US expected to cost up to $22.5bn, the overwhelming price of PTC has also slowed its progress, as rail owners have directed funding towards new locomotives and other projects.

Susan Fleming, GAO director of physical infrastructure issues, says the installation and testing of new technologies have necessitated large, multi-year projects, many of which are still far from completion.

“Based on our analyses, small commuter railroads as well as large commuter railroads serving several million riders a month may face challenges meeting the 2018 deadline or criteria necessary for an extension,” she says.

Ensuring interoperability

Some US railroads have boasted of their successful implementation of PTC hardware. For example, BNSF says it has equipped more than 11,500 route miles with PTC infrastructure and equipped 100% of its locomotives with the technology.

Nevertheless, testing the systems and training staff to ensure they meet the FRA’s specification will be a major factor in determining whether railroads will meet the 2018 deadline. Additionally, the FRA must review each railroad’s PTC safety plan and certify systems after development and testing is completed.

Crucial to the PTC system is interoperability; passenger, commuter and freight trains must be able to seamlessly operate and communicate across different railroad systems.

“Many of the commuter railroads are currently focused on initial implementation activities and told us they have not started tackling some of the later stage implementation steps, such as interoperability, which is a key to ensure the full safety benefits of PTC,” says Fleming. “Interoperability will also require extensive coordination between host and tenant railroads.”

The FRA estimates that field testing takes at least one year, but GAO found that 14 commuter railroads plan to begin this work less than a year before the 2018 deadline. Fleming says that many railroads told the GAO that they have experienced software issues, which has meant testing has taken a lot longer than planned.

“For example, some railroads mentioned issues arose as they worked to get their [BOS] up and running and encountered issues upgrading to the latest software version and working out the bugs,” she says.

"As railroads that are further ahead with implementation work through software issues and the technology upgrades resolve those issues, railroads that are further behind should benefit from the technical issues being resolved and the improved functionality of systems.”

Amtrak may suspend services not using PTC. Credit: Amtrak/Phil Gosney.

Supporting safer railroads

Under the US Congress ruling, railroads that fail to meet the December 2018 deadline are able to extend their PTC installation projects for two years’ time, but only for ‘certain non-hardware, operations aspects of PTC system implementation’.

In January and February, leaders of the FRA hosted face-to-face meetings with railroads to evaluate the statues of the PTC programme and to discuss what steps were needed to meet their quotas.

“It is the railroads’ responsibility to meet the congressionally mandated PTC requirements,” said FRA administrator Ronald Batory in a statement. “The FRA is committed to doing its part to ensure railroads and suppliers are working together to implement PTC systems.”

In addition, the GAO has recommended FRA identify and to adopt a method for systematically communicating information to railroads and use a risk-based approach to prioritise its workload and resources. Nevertheless, it will ultimately be up to rail owners to ensure that systems are tested and installed as soon as possible, to reduce the likelihood of further deadly rail accidents.