Emerging Technologies in Transportation Casebook/Positive Train Control
Positive Train Control (PTC) is an advanced avoidance system mandated by Congress in The Rail Safety Improvement Act of 2008 for all Class I railroads and passenger rail operators. The technology is being installed on all main line track where intercity passenger railroads and commuter railroads operate and lines carrying hazardous materials. PTC introduces continuous GPS-based location and speed tracking, with more sophisticated on-board wireless technology for enforcing movement authority from a centralized control center, wherever the vehicle may be. PTC will be inherently more reliable, and offer greater real-time functionality than conventional systems. PTC is expected to be implemented over approximately 60,000 miles of track in the United States.
Annotated List of ActorsEdit
- U.S. Congress - Legislative Body that enacted the Rail Safety Improvement Act of 2008 mandating the implementation of Positive Train Control
- Federal Railroad Administration (FRA) - Responsible for rule making and certification of PTC
- Class I freight Railroads in the United States - BNSF Railway, Canadian National Railway, Canadian Pacific, CSX Transportation, Kansas City Southern Railway, Norfolk Southern, Union Pacific Railroad
- Intercity Passenger Railroad - Amtrak
- Commuter Rail - 28 Systems in the United States
- Federal Communication Commission (FCC) - ~22,000 Antennae need approval, Two months to review each submission, Historic Preservation Laws
- Association of American Railroads (AAR) - Industry Trade Group representing major frieght railroad companies in North America
- National Transportation Safety Board - Responsible for investigating train accidents
Timeline of EventsEdit
- 1969 - National Transportation Safety Board calls for the development and implementation of more advanced train control systems after head-on collision between two commuter trains in Connectiuct. (4 dead, 43 Injured) 
- 1990 - National Transportation Safety Board (NTSB) adds Postive Train control to ins "Most Wanted List"
- 1994 - Federal Railroad Safety Authorization Act of 1994 requires the Secretary of Transportation to submit a report to the Congress on the development, deployment, and demonstration of the positive train control systems
- August 1999 - Railroad Safety Advisory Committee submits "Implementation of Positive Train Control Systems" to the Federal Railroad Administrator
- March 7, 2005 - FRA establishes regulatory requirement (49 CFR Part 236 Subpart H) standards for the development and use of processor-based signal and train control systems.
- September 12, 2008 - Collision between a MetroLink commuter train and freight train in Los Angeles (25 dead, 135 injured) 
- October 1, 2008 - Congress passes Rail Safety Improvement Act requires all Class I railroads and passenger railroads to implement a PTC system
- October 8, 2008 - Class I Railroads reach agreement on establishing Positive Train Control Interoperability Standards
- January 15, 2010 - FRA establishes rulemaking (49 CFR Part 236 Subpart I) for mandated Postive Train Control
- April 16, 2010 - Class I Railroads submit PTC implementation plans to FRA
- July 12, 2012 - FRA modifies rule to allow railroads to not implement PTC on rail segments that will not transport toxic inhalation contents or passengers.
- May 12, 2015 - Derailment of Amtrak train North of Philadelphia that could have been prevented with PTC (8 were killed and over 200 injured)
- October 29, 2015 - Congress passes H.R.3819 - Surface Transportation Extension Act of 2015 which extends Postive Train control deadline three years
- December 18, 2015 - Amtrak activates final stretch of Positive Train Control (PTC) along the Northeast Corridor (NEC)
- December 31, 2015 - Original date for implementation of Positive Train Control
- December 31, 2018 - Current deadline to implement Positive Train Control
Maps of LocationsEdit
Positive Train Control will be implemented on ~60,000 miles of track throughout the United States
Clear Identification of Policy IssuesEdit
- Unfunded mandate ($9 Billion) - PTC is the single-largest regulatory cost ever imposed on the industry by the Federal Railroad Administration
- Interoperability - A key objective of PTC regulation was to unify a disparate group of safety technologies under a common set of standards
- Radio Frequency Spectrum - 220 MHz frequency for the PTC wireless communications network
- Certification Process - Prior to certification and revenue service, each rail company is required to submit to FRA a PTC Implementation Plan (PTCIP), Development Plan (PTCDP), and Safety Plan (PTCSP)
- Barriers to Market Entry
- Fatality Cost - According to the Federal Railroad Administration (FRA), an average of 1,870 derailments and 192 train collisions, resulting in 428 injuries and 12 fatalities, occurred annually from 2001 to 2012, excluding accidents at highway-rail crossings, which PTC does not prevent. Most of the incidents occur in rail yards and are generally less severe than PTC-preventable accidents. In 2012, 9 fatalities occurred from train collisions or derailments, 235 fatalities occurred at highway-rail grade crossings, and 437 fatalities resulted from trespassing on railroad property or right-of-way.
Narrative of the CaseEdit
Railroads have been implementing safety systems to reduce accidents since the early 20th century. Several high profile accidents have pushed the National Transportation Safety Board, Congress, and the Federal Railroad Administration to advance technologies to improve the safety of the railroad network. Automatic Train Control (ATC) and Automatic Train Stop (ATS) signal systems have been in use along some sections of track for many years. However, most of these systems are ‘reactive’ systems, which means they wait for train engineers to acknowledge alarms and would not prevent collisions under all circumstances. As technologies continued to advance the FRA in 2005 submitted standards for Processor-Based Signal and Train Control Systems. The implementation of any system based on this directive was voluntary and the new system just had to show safety was not reduced from what was in place before.
After the train collision in Chatsworth, CA, Congress passed the Rail Safety Improvement Act of 2008 (RSIA). This mandated Positive Train Control systems be implementation based on the following guidelines by December 31, 2015.
Designed to prevent:
- Train-to-train collisions
- Derailments caused by excessive speed
- Unauthorized incursions by trains onto sections of track with maintenance activities
- Movement of a train through a track switch left in the wrong position
Installed on any tracks that carry:
- More than 5 million gross tons of freight per year
- Toxic by inhalation materials
. In addition, each system needed to be interoperable with other PTC systems installed by other railroads.
There are no official technical specifications which PTC must meet; Congress and the Railway Safety Improvement Act currently allow rail companies flexibility in choosing the exact design of their PTC infrastructure. Nevertheless, all PTC systems possess share four basic components:
- Back Office Server System - Stores speed restriction, track geometry, and wayside signaling databases. Also interfaces with back office server systems, dispatch systems, and communications segments.
- Onboard System - Software and hardware within the locomotive responsible for monitoring the train's movement and performing certain control functions such as braking.
- Wayside Signal System - Integrated with the back office server and the onboard system. Monitors switch position, signal indication, and other wayside signal systems.
- Communication Network Component - The wired and wireless networks that allow messages to be exchanged between the other components of the PTC system; the back office server, onboard system, and wayside signal system.
In the United States, those companies that have begun implementing PTC technology are doing so with an "overlay type system." This involves integrating the PTC components described earlier with already installed signals, switches, sensors, and wayside infrastructure. Under this system, the four components share information with at least one other component but each is independently responsible for important tasks in the PTC operation. For example, the base office server stores the wayside signaling databases but does not transmit it directly to the onboard system. Instead, it transmits the information to the wayside system which is independently responsible for monitoring the operation of the other rail signals for which it is overlaid. The wayside system will alert the train operator whether a signal on the track is malfunctioning but it is does not monitor whether the train operator is complying with the signals. The onboard system is responsible for separately processing information from the base office server and the wayside signals and ensuring that the train operates accordingly. The potential downside to this configuration is that is relatively disjointed and relies on a multitude of various links and separate communication networks to operate properly.
Communications-Based Train Control, or CBTC, is another form of PTC implementation that solves some of these concerns. CBTC uses a computer-aided dispatching system which sends out information and commands to all the trains and other PTC components throughout the entire network. CBTC relies on GPS technology to maintain real-time train location and speed data. The system processes headway distance and necessary braking distance based on wheel-rail friction, brakes wear, track grading, and other factors. CBTC provides superior safety capabilities to an overlay system because of its monitoring precision and the speed it is capable of coordinating and sending control commands to trains through its network. It would also likely provide for improved scheduling and fuel efficiency. However, CBTC is significantly more expensive to install than the overlay system. To work properly, rail networks would need constant and seamless communication coverage which requires installing additional radio towers and fixed transponders. To date, American rail companies have not seen it financially suitable to install an entirely CBTC modeled system. However, in the United States and elsewhere, operators have begun implementing elements of the computer-aided dispatching system. Some of them are included in the PTC system examples listed below:
- ACSES - Advanced Civil Speed Enforcement System - Transponder-based system, in use on Amtrak's Northeast Corridor .
- ETMS - Electronic Train Management System - GPS and communications-based system being deployed by BNSF Railway.
- I-ETMS - Interoperable Electronic Train Management System - GPS and communications based system planned for use by CSX Transportation, Norfolk Southern Railway, and Union Pacific Railroad.
- ITCS - Incremental Train Control System - GPS and communications based system used by Amtrak on 110 mph Michigan line.
- E-ATC - Enhanced Automatic Train Control - System that uses an underlying automatic train control (ATC) system, in conjunction with other “enhanced” features or systems to achieve the core required functionalities of PTC.
Interoperability is a major challenge to achieving nationwide PTC implementation. Rail companies often run their locomotives on track that is owned by a different company. In many cases, the company that owns the track has installed PTC technology that is different from the PTC technology installed on the locomotive. To be interoperable, the PTC components in and around the track and within the onboard system of the locomotive must be compatible. Many companies were already developing systems with PTC components before passage of the Rail Safety Improvement Act of 2008. Since then, the Federal Railway Administration (FRA) has mandated that PTC systems be interoperable when one rail company's locomotive is operating on the track of another company. This has led to the FRA issuing "type approvals" to rail companies for PTC systems that are deemed to allow for this interoperability. For example, I-ETMS or Interoperable Electronic Train Management Systems has received FRA type approval and is used by CSX Transportation, Norfolk Southern Railway, and Union Pacific Railroad (BNSF Railway is slated to upgrade to I-ETMS at a future date). These companies will presumably be able to operate their PTC technology seamlessly over each other's track wherever the I-ETMS is in place. However, these are only a few of the rail companies that operate throughout the United States. Successful nationwide PTC interoperability will require all companies that share track to agree on a common PTC system. Short of agreeing upon compatible PTC systems, rail operators would have to install at least two PTC systems if their companies system does not correspond with that of the track owner. This is prohibitively expensive to most operators is unlikely to be seen throughout the country.
The other challenge to interoperability is the need to share common radio spectrum. PTC equipment hardware and software must not only be compatible across operators, they also be able to communicate with one another. Although utilizing multiple frequencies is an option, it is expensive and most rail operators prefer that they share a single frequency with operators they share track with. The rail companies have identified the 220 MHz frequency band as the most desirable spectrum to meet their needs. Union Pacific Railroad, Norfolk Southern Railway, CSX Transportation, and BNSF Railway have merged as a consortium, PTC-220 LLC, that has purchased frequencies in the 220 MHz range. To reach the goal set out by the Rail Safety Improvement Act, however, all the rail companies must determine how they will obtain and share radio frequencies with other operators with which they share track. The PTC-220 LLC consortium and other rail operators have requested that the Federal Communications Commission (FCC) allocate the entire 220 MHz to the rail companies for exclusive implementation of PTC. Amtrak and others have even requested that the FCC allocate from 217-222 MHz spectrum and licenses to ensure they have suitable spectrum for congested areas. To date, the FCC has not designated any radio spectrum be allocated solely for PTC implementation. One of the concerns is that the FCC has already auctioned several licenses within the 220 MHz to other entities. The rail operators argue that the FCC should reallocate this spectrum to them under public safety provisions, but the owners of the licenses insist this would be an unfair forceful transfer of licenses from one private party to another. They argue that the rail operators could simply lease spectrum from them. The rail operators counter that leasing spectrum from current 220 MHz license owners would be prohibitively expensive. State-owned rail operators, for instance, have considerable difficulty raising funds and requiring them to purchase or lease license from private owners may be unfeasible. Further complicating matters is the fact that many rail operators are hesitant to purchase PTC radio equipment without knowing if and what the radio spectrum standard will be. If 220 MHz does not become the official industry standard, rail companies may waste money on radios that will not cannot communicate with an adjacent operator's PTC equipment.
In August 2015, the FRA reported the Congress that PTC would not be implemented by the December 31, 2015 deadline. They indicated the following challenges have prevented railroads from implmententation the technology: Wireless Spectrum Availability, Limited Number of Suppliers of PTC technology, Potential Radio Interference, Safety Plans. On October 29, 2015, Congress passes H.R.3819 - Surface Transportation Extension Act of 2015 that extended the Postive Train Control implementation mandate an additional three years to December 31, 2018.
As of June 2015, the following is scheduled to happen by the end of 2016:
- 38% of 60,153 route miles will have PTC.
- 63% of 22,066 locomotives will be equipped with PTC.
- 51% of the 114,515 employees requiring training will be PTC-qualified.
- 87% of the more than 32,654 trackside signal systems will be PTC-ready.
- 77% of the 3,968 base station radios will be installed.
Should Congress authorize a unfunded safety mandate on freight and passenger railroads?
Is preventing ~11 deaths a year worth the investment?
Should Congress allocate radio spectrum (220 MHz for example) strictly for PTC? If so, should Congress require that all freight and commuter lines operate on that radio spectrum to address interoperability concerns?
Additional Readings and InformationEdit