Positive Train Control: State of the Industry

Positive Train Control (PTC) is an advanced system designed to prevent train-to-train collisions, over-speed derailments, unauthorized incursions into work zones, and train movement through switches left in the wrong position. PTC monitors and, if necessary, controls train movement in the event of human error

With the passage of the Rail Safety Improvement Act in 2008, 41 commuter, Class I freight, and short line railroads were required to install PTC. Also, 60,000 miles of track would need to be equipped with wayside components, and trains that operate over another railroad’s tracks must be interoperable, that is, compatible with the host railroad’s PTC software, which often requires extensive custom engineering and installation. 

Commuter railroads alone will spend an estimated $4.1 billion to achieve full implementation of PTC. While there have been federal grants made available to aid public agencies in implementing PTC, much of these monies were authorized after the first PTC deadline, and still, federal dollars are slow in getting to the grantees. 

At a March 1, 2018 hearing of the Senate Commerce Committee, the DOT Inspector General noted that “nearly $15 million of the $25 million awarded in August 2016 had not been obligated to the grantees. Similarly, out of the $197 million authorized for PTC implementation under the FAST Act, approximately $190 million had not been obligated to the grantees, even though award selections were announced last May [2017].” 

Further, one recipient pointed out that the amount of federal money in PTC-specific grants ($15.8 million) they received was minimal compared to the $310 million in federal and state funds they had to divert to implement PTC. Diverting these funds, however, necessitated a delay in completing state-of-good-repair projects elsewhere in the system. 

In addition, not receiving necessary funding meant a subsequent delay in agencies being able to access the limited number of qualified suppliers and system integrators with the expertise to deliver PTC systems.  

Industry-wide dependence on too few qualified suppliers has eaten away at contingencies built into the implementation timelines of railroads working to deliver PTC by December 2020.  In July 2019, GAO reported that “vendor and software issues are currently major or moderate challenges for PTC implementation….(and) certain software functionality had yet to be developed, tested, and implemented to address reliability issues and facilitate interoperability.”

The 41 railroads required by Congress to implement positive train control (PTC) systems by December 31, 2018 have submitted documentation that they assert is sufficient to meet the statutory requirements for system activation or the statutory requirements to qualify for an alternative schedule (“extension”) for up to two additional years to complete full implementation.

You can find the FRA’s quarterly update on railroads’ PTC implementation status here: https://www.fra.dot.gov/app/ptc

A Timeline:

1990: The National Transportation Safety Board introduced its now-annual list of “most wanted” transportation safety recommendations. A safety system referred to as positive train control was included on that inaugural list, and thereafter, until Congress passed the Rail Safety Improvement Act in 2008.

1994: An analysis undertaken by the FRA at the behest of Congress showed that the safety benefits of a system of positive train control did not justify a mandate.

2004: Ten years later, in response to a request from the Senate Appropriations Committee, the acting administrator of the Federal Railroad Administration submitted an updated analysis of the cost and benefits of positive train control and related systems. It took into account advances in technology and system savings, and analysis of the business benefits, such as improved traffic flow, a modal shift of goods from trucks to rail, and the concurrent environmental benefits. 

The report stated, in part:

  • There is no vendor offering immediate sale of such a system.

  • Predicted eight years for development and installation if a funding mechanism were already in place.

  • If the railroads had thought there were business benefits (that is, improved traffic flow and schedule performance as a measure of ROI) they would have already invested in enhancing operations through PTC.

2008: In September, a passenger to freight train collision in Chatsworth, California left 25 people dead and 135 injured.  The engineer at fault in that incident was found to have been distracted by texting.

Within a month, Congress had passed the Rail Safety Improvement Act (RSIA), requiring certain railroads to install communications-based train control systems to overcome human error or distraction.  The mandate required positive train control (PTC) systems to be implemented – installed and interoperable - by December 31, 2015.  

There was no federal funding mechanism envisioned as part of the legislation.

2010:  The FRA issues final guidance to the railroad industry for PTC implementation as a result of the Rail Safety Improvement Act.

 As defined by the Federal Railroad Administration, “PTC uses communication-based/process-based train control technology that provides a system capable of reliably and functionally preventing train-to-train collisions, overspeed derailments, incursions into established work zone limits, and the movement of a train through a main line switch in the wrong position.”

It must be noted that PTC does not prevent grade crossing or trespasser incidents, which individually result in far more deaths each year.  And PTC does not it initiate in-terminal stops.  [For more, see “What PTC Does Not Do” below]

2013: In June, the GAO issued Preliminary Observations on Federal Safety Oversight and Positive Train Control Implementation, finding that “railroads may not be able to fully implement PTC by the 2015 deadline ….because of the many interrelated challenges caused by the complexity and breadth of PTC implementation. For example, PTC components, such as back office servers…are still in development. In addition, the need to integrate PTC components and field test the system is a time- and resource-consuming process. …In attempting the implement PTC by the 2015 deadline, railroads will be making choices that could introduce financial and operational risks. For example…without adequate time for field testing, PTC systems could potentially malfunction or fail more frequently, causing system disruptions.”

2015/September: As the deadline approached the GAO issued another review of PTC implementation progress. It found that a majority of commuter railroads not meet the statutory deadline, and those that were close to meeting the deadline were facing risks related to interoperability of their PTC systems with those of other railroads.

“Development of a major component of the Interoperable Electronic Train Management System (IETMS), being installed by the largest railroads, continues to be delayed. Smaller railroads have been challenged in obtaining PTC support and components due to the limited number of vendors.

“Some host railroads have many tenant railroads and the host railroad must work with the tenants to determine if the tenants should equip with PTC. …Railroads must ensure their systems are interoperable, as task that can be challenging when multiple railroads are involved.”

2015/October: Acknowledging these substantial remaining challenges, Congress extended the implementation window. The PTC Enforcement and Implementation Act assigned a new, interim deadline of December 2018, and, under certain qualifying criteria, an ultimate deadline of December 2020.

2018/March: GAO reports Many Commuter Railroads Still Have Significant Additional Implementation Work and Opportunities Exist to Provide Federal Assistance. “GAO’s analysis …found that from 7 to 19 commuter railroads may not complete the milestones before the 2018 implementation deadline or qualify for an RSD-based extension.

“…With the year-end 2019 approaching, and an anticipated significant increase in FRA’s workload, targeting resources to the greatest risk can help better ensure that FRA effectively fulfills its oversight responsibilities and provides commuter railroads the information they need to prepare for the 2018 deadline or seek an extension.”

2018/September: Most Passenger Railroads Expect to Request an Extension and Substantial Work Remains Beyond 2018, GAO. “Challenges related to PTC implementation and FRA’s resources raise questions as to the extent FRA and the passenger railroad industry are poised for full PTC implementation by December 31, 2020. Most passenger railroads anticipate needing an extension, leaving substantial work for both railroads and the FRA to complete before the end of 2020. …In addition, passenger railroads reported that they continue to face many of the same challenges GAO previously identified, such as software defects and limited industry-wide availability of vendors. Further, passenger railroads expressed concern that FRA’s workload will markedly increase as railroads submit requests for extension approval.”


When the Rail Safety Improvement Act was passed in 2008 it was estimated that installing PTC systems would cost the publicly-funded commuter railroads $2 billion to meet the congressional mandate.  But PTC was still not yet a proven, nor an off-the-shelf technology.  And, system components had to be customized to every individual railroad’s unique operating environment.

Early implementation progressed in fits and starts, with unanticipated challenges interrupting the timeline set by Congress.

  • FRA guidance: More than a year after Congress passed the RSIA, the Federal Railroad Administration issued its guidance document in January 2010.

  • Access to spectrum: The private Class 1 freight railroads formed PTC220 LLC and bought frequency to meet their spectrum needs. Meanwhile, the publicly-funded passenger railroads were struggling to find spectrum to purchase on the open market. Repeated pleas to the FCC to recognize PTC’s spectrum requirements as “safety critical” went unheeded. 

  • Funding challenges: Without federal resources, public agencies were forced to reevaluate their capital plans to prioritize PTC over locally identified state of good repair/critical safety needs.

  • Access to qualified suppliers: Funding/financing challenges for publicly-funded commuter railroads delayed their access to the limited number of qualified suppliers and system integrators with the expertise to deliver PTC systems.


At the request of Congress, the US Government Accountability Office (GAO) undertook a series of industry reviews to evaluate the railroads’ implementation progress and the efficacy of federal oversight.  

Two years after the RSIA was passed, in 2010, the GAO cited the following challenges and obstacles: 

  • Software to test components remains in development 

  • Publicly-funded commuter railroads may have difficulty covering the $2 billion that PTC is estimated to cost them (*that figure later doubled) 

  • The cost of PTC alone could create delays if funding is not available 

  • The cost of PTC could require that railroads divert funding from other critical areas, such as maintenance 

  • Railroads’ other critical needs may go unmet if funding is diverted to pay for PTC 

And, in 2013, two years in advance of the 2015 deadline, in another report the GAO noted:

  • PTC components…are still under development 

  • The need to integrate PTC components and field test the system is a time and resource consuming process 

  • Without adequate testing, PTC systems might be more prone to reliability issues 

  • In attempting to implement PTC by the 2015 deadline, railroads could be making choices that could introduce financial and operational risks 

  • Railroads that operate as tenants on host rail lines must wait until the host fully equips the lines they operate on

  • The ability of railroads to meet the (2015) deadline may be affected by the interoperability of their PTC system with those of other railroads and whether they can obtain final system approval by the FRA

  • Development of a major component of the Interoperable Electronic Train Management System (IETMS), being installed by the largest railroads, continues to be delayed

  • Smaller railroads have been challenged in obtaining PTC support and components due to the limited number of vendors

Some host railroads have multiple tenant railroads operating over their tracks. Host railroads must work with each tenant to determine if the tenant should equip its trains with PTC. One large freight railroad said it must make this determination for 260 tenants. PTC is not complete until host and tenant systems are interoperable, a task that can be challenging when multiple railroads are involved.

Acknowledging these substantial challenges, in late 2015 Congress extended the implementation window to 2018, and under certain criteria, and ultimate deadline of 2020.

PTC Background

How does PTC work?

A Positive Train Control System will send visual and audible information to train crew members about areas where the train needs to be slowed or stopped. This information includes the status of approaching signals, the position of approaching switches, speed limits at approaching curves and other reduced-speed locations, speed restrictions at approaching crossings, and speed restrictions at areas where work is being performed on or near the tracks. PTC communicates with the train’s onboard computer, which audibly warns the engineer and displays the train’s safe braking distance based on the train’s speed, length, width, weight, and the grade and curvature of the track. If the engineer does not respond to the audible warning and screen display, the onboard computer will activate the brakes to safely stop the train.

What are the key components of PTC?

There are three main elements of a PTC system, which are integrated by a wireless communications system:

1.     The Onboard or Locomotive System monitors the train’s position and speed and activates braking as necessary to enforce speed restrictions and unauthorized train movement into new segments of track. 

2.     The Wayside System monitors railroad track signals, switches, and track circuits to communicate authorization for movement to the locomotive. 

3.     The Back Office Server is the storehouse for all information related to a particular rail network and trains operating across it—speed limits, track composition, speed of individual locomotives, train composition, etc.—and transmits the authorization for individual trains to move into new segments of track.  

Will PTC prevent all railroad-related accidents and incidents?

PTC cannot stop a train approaching an obstructed street-level crossing, nor will it prevent a vehicle from driving into or around lowered railroad crossing gates.  PTC cannot prevent trespassers from making their way onto the tracks, nor notify the train’s braking system of the trespasser. A conductor’s visual observation of either of these incursions does not provide for adequate braking time for a train weighing 2,000 tons or more.

What PTC does not do: 

  • PTC does NOT prevent grade crossing or trespasser incidents.  Nearly 96% of rail-related (i.e., not PTC-preventable) fatalities are attributable to grade crossing incursions (273 deaths and 813 injuries in 2017) and trespassing (560 deaths in 2017).

  • PTC does NOT initiate in-terminal stops:  the current generation of technology being installed has not been designed to bring trains to a stop to prevent end-of-track collisions, such as those incidents at Atlantic Terminal (LIRR, 1/4/17) and Hoboken (NJT, 9/29/16).  A robust Obstructive Sleep Apnea screening and treatment program, however, might have prevented both of these particular incidents. 

Why is PTC still not complete?

As the GAO noted in its multiple reports to Congress, PTC is not an off-the-shelf product. Positive train control is a system of technologies that must be custom designed to meet the requirements of each railroad’s particular operating conditions, and the system design must be compatible with that of the other railroads operating over the same tracks, often requiring extensive custom engineering and installation.  

Prior to full implementation, rigorous testing must be conducted and verified on all components of PTC. Railroad employees involved in the control, operation, and movement of trains must be fully trained. 

Once an operator has completed their PTC installation and training they are then required to test and prove the interoperability of their sy stem with those installed by any other carriers operating over the same tracks.  PTC system completion depends on engagement and coordination with the other carriers operating over the same tracks.

Simply put, host and tenant railroads that have already completed their installation, testing and training will still need to prove interoperability with other entities before they qualify for final sign-off by the FRA..  

Extending the Deadline

Acknowledging the challenges to activating a fully interoperable PTC system, Congress passed the PTC Enforcement and Implementation Act of 2015, extending the implementation timeline to 2018, with the option for up to an additional two-year extension under certain qualifying circumstances.

Ten years after the RSIA mandate, current estimates indicate that it will cost $4.1 billion to complete the implementation of PTC on commuter railroads alone – more than double the original estimate. Maintenance and continuous upgrades are expected to cost the publicly-funded commuter railroads 10 – 20% of their annual capital costs.   

How much will it cost?

Commuter railroads will spend roughly $4.1 billion to implement PTC.  And continuous upgrades and maintenance are expected to cost commuter railroads 10 – 20% of their annual capital costs for the foreseeable future.

 (It is estimated that the cost to install PTC across all 41 railroads will be $14 billion.)

In nine years following the Chatsworth accident, up to the end of the federal fiscal year 2017, Congress had made available just $1.3 billion in grant funding support for PTC installation for the entire group of 41 effected properties, both passenger (public) and freight (private).

As publicly-funded entities, many of the nation’s commuter railroads were forced to defer other critical safety or capital programs in order to comply with the federally mandated PTC implementation schedule.  Some agencies bonded to finance their system installation, which, paradoxically, now make the railroad ineligible for the PTC grant funding now being made available. And federal grant conditions do not allow railroads to pay for the projects that were deferred in order to redirect local funding to PTC.  Further, at this stage in the installation/implementation process, given the timing of the release of the notice of funding opportunity, awards will necessarily be focused on next generation improvements to PTC and not the initial, mandated implementation.