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Policy Issues


Positive Train Control

Freight Rail Policy Stance: Freight railroads are committed to developing, installing and implementing Positive Train Control (PTC).

Why This Matters: PTC is a set of highly advanced technologies designed to make freight rail transportation — already one of the safest U.S. industries — even safer by automatically stopping a train before certain types of accidents occur.

Key Takeaway: The Class I freight railroads are on track to meet all statutory deadlines for this important safety technology, which will add another layer of protection to America's rail network.

What is PTC?

PTC is an unprecedented, advanced set of technologies that will automatically stop a train before certain human error incidents occur. Under the Rail Safety Improvement Act of 2008 (RSIA), passenger railroads and Class I freight railroads must install PTC on main lines used to transport passengers or toxic-by-inhalation (TIH) materials.

What will PTC do?

PTC will prevent:

  • Train-to-train collisions
  • Derailments caused by excessive speed
  • Unauthorized train movement onto sections of track where maintenance activities are taking place
  • Movement of a train through a track switch left in the wrong position


PTC will not prevent:

  • Accidents caused as a result of track or equipment failure
  • Improper vehicular movement through a grade crossing
  • Trespassing on railroad tracks
  • Certain types of train operator error


When will PTC be ready?

The RSIA originally called for passenger railroads and Class I freight railroads to install PTC by the end of 2015. Congress extended the deadline in October 2015 and established benchmarks for installation and implementation because they recognized rushing development and installation would sharply increase the likelihood that PTC would not work as it should. The Class I railroads are on track to meet all statutory deadlines.

Installation Deadline: December 31, 2018

  • All hardware installed
  • All radio spectrum acquired
  • Over 50% of PTC territory or route miles implemented
  • All required employee training completed

Implementation Deadline: December 31, 2020

A further extension up to 24 months is available to railroads that meet the 2018 installation deadline requirements. This allows railroads enough time to test and ensure that the system is fully interoperable. Interoperability means that the system works with any PTC-equipped locomotive running on any of the railroad tracks through the United States where PTC is required. 

  • Testing completed
  • Full PTC implementation across the network 

What progress has been made?

Based on funding, existing technology, different operating systems and a variety of other factors, Class I freight railroads and passenger rail lines are all at different levels of PTC installation and implementation. Railroads have made significant progress on PTC installation, and the Class I railroads will meet the 2018 installation deadline. As of December 2017, Class I railroads have:
  • Equipped 78% of required locomotives with PTC
  • Installed PTC on more than 72% of required track segments
  • Installed 97% of required radio towers
  • Trained 87% of required employees on PTC
  • Implemented PTC on 56% of required route miles

How does the technology work?

A PTC system must account (in near real-time) for a number of constantly changing factors that measure the appropriate train stopping distance. These measures include train information (weight, length); track composition (curvature, terrain); train speed and train authority (authorization to move across a stretch of track). To do this, a PTC system consists of three main segments that are integrated by a wireless communications system. 

  1. Locomotive Segment: Monitors a train's position and speed and activates braking as necessary to enforce speed restrictions and unauthorized train movements.
  2. Wayside Segment: Monitors railroad track signals, switches and track circuits and communicates authorization for movement to the locomotive.
  3. Back Office Segment: Stores millions of rail network data points as encrypted information (e.g., speed limits, track layouts, speed of other trains on the system, train compositions, etc.) and transmits the authorization for individual trains to move into new track segments.


What do railroads need to do?

PTC has never been attempted at this scale anywhere in the world. For this ground-breaking technology to work correctly, Class I railroads must:
  • Precisely geomap more than 54,000 route-miles and more than 450,000 field assets (mileposts, curves, grade crossings, switches, signals, etc.) along that right-of-way. 
  • Install PTC technology on more than 17,200 locomotives. 
  • Install more than 24,000 “wayside interface units" (WIU) custom desinged for each location, which will transmit information from signal and switch locations along the right-of-way to locomotives and railroad facilities. 
  • Install PTC technology on nearly 2,100 switches in non-signaled territory and complete signal replacement projects at some 14,500 locations.
  • Develop, produce and deploy a new radio system specifically designed for the massive data transmission requirements of PTC at tens of thousands of base stations and trackside locations, and on more than 17,200 locomotives. 
  • Develop the back office systems and upgrade dispatching software to incorporate the data and precision required for PTC systems.

How do railroads test PTC?

PTC must work right; there are no shortcuts when it comes to safety. It is not enough to get PTC to operate across a single railroad's footprint; it must be interoperable. Each railroad is developing a PTC system from the ground up that meets their unique requirements. As they develop and install each component, it must pass multiple, rigorous testing requirements.

  • Lab Testing: Software and hardware tests begin in controlled lab settings then move to the field to confirm that they work in the real-world. Engineers repeat these testing cycles when there are software updates or when new components of PTC are installed.
  • Field Testing: The initial field tests ensure PTC works in operation on one railroad's network. The next step – and the larger challenge — is to make sure these individual PTC systems are completely interoperable and work together seamlessly. Put another way, a CSX locomotive must behave like a Norfolk Southern locomotive when it's traveling on Norfolk Southern's tracks; a BNSF locomotive must be able compatible with Union Pacific's PTC system when it's on Union Pacific's tracks, and so on. 
  • FRA Certification: The Federal Railroad Administration (FRA) must certify each railroad's PTC systems after the development and testing of the components are complete.  

How much does PTC cost?

The AAR estimates that, as of the end of 2017, freight railroads together have spent more than $8 billion — of their own funds, not taxpayer's — on PTC development and deployment. Railroads expect to spend more than $10 billion by the time PTC is fully operational nationwide. This does not include the hundreds of millions of additional dollars needed each year to maintain the railroads' PTC systems once they are initially installed.