Positive Train Control (PTC)

What is Positive Train Control (PTC)?

Positive Train Control (PTC) is a processor-based/communication-based control system designed to prevent railway accidents. PTC technology is designed to automatically control train speeds and movements should an engineer not take suitable action for a given situation.

For example, PTC can avert a potential collision by bringing a train to a stop before it passes a signal with a stop indication or before it diverges on an improperly lined switch.

PTC systems reliably and functionally prevent:

  • Train-to-train collisions
  • Overspeed derailments
  • Movement into an established work zone
  • Advancing through a main line switch in the improper position

PTC systems also allow for equipped locomotives crossing another railroad’s PTC-equipped territories to communicate with and respond to that railroad’s PTC system, including uninterrupted movements over property boundaries.

Federal Mandate

Congress requires Class I railroads and entities that provide regularly scheduled intercity or commuter rail passenger transportation to implement PTC systems by December 31, 2018.

It is estimated this equates to approximately 60,000 miles of track and will involve approximately 20,000 locomotives nationwide. If some key implementation and installation milestones are met, railroads may be eligible to obtain an extension of no later than December 31, 2020 to complete certain non-hardware, operational aspects of PTC system implementation, subject to the Secretary of Transportation's approval.


Under current law (49 U.S.C. 20157), commuter railroads were required to meet the following milestones by  December 31, 2018. As defined in 49 U.S.C. 20157(a)(3)(B), they are to have:

  • Installed all PTC hardware (wayside and onboard equipment);
  • Acquired all necessary spectrum for PTC implementation; 
  • Completed all employee training; 
  • Initiated testing on at least one territory subject to the PTC requirement (or other criteria); and 
  • Submitted a revised plan and alternative schedule to the Secretary of Transportation for implementing a PTC system.  

Now that VRE has met those milestones, one of the biggest challenges is interoperability. VRE must ensure our PTC implementation is seamlessly operational for both host and tenant operators. This will require thorough communication and coordination between VRE and our host railroads CSX and NS. That work is going on now and is progressing well. VRE is confident our trains will be operating under full PTC enforcement well before the December 31, 2020 deadline.