PTC, a different approach

Written by Carl Nash, Ph.D.
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Major train derailments and collisions can be spectacular. Their economic and environmental consequences are considerable, and they kill and injure people. In response, over the past 40 years, pressed by the National Transportation Safety Board (NTSB), the Federal Railroad Administration (FRA) and Congress (by statute in 2008) the railroads have been implementing Positive Train Control (PTC) systems to reduce the potential for these crashes.

Actually, U.S. railroads are quite safe for passengers. An average of five people die in train crashes each year, slightly more than are killed in motor vehicle crashes in an hour. The number of serious injuries among train occupants is similarly low. On the other hand, nearly 700 “trespassers” die annually after being struck by trains while on or near railroad tracks, and about 100 more are killed in vehicles struck by trains at grade crossings. These casualties are a consequence of two issues: Trains cannot be stopped quickly, and it is difficult to keep people away from railroad tracks. PTC will do nothing to prevent trespassers from being struck by moving trains.

According to the FRA: “PTC systems are integrated command, control, communications, and information systems designed to prevent train accidents by controlling train movements with safety, security, precision, and efficiency.” The nation’s railroads and the FRA have spent about $10 billion on a variety of PTC systems, and will apparently spend a few billion more to complete them.

Railroad transportation in the an important but hoary industry in desperate need of a 21st Century overhaul. It matured a century ago. Train dispatching, safety, maintenance and such were mostly developed in the 20th century. More recent technologies are mostly used to provide an electronic substitute or enhancement of what had been done by hand. Modern communications—radio, microwave, the Internet—have replaced the telegraph and even telephones.

Road users have the advantage of well-developed, real-time, satellite-based navigation systems. There is no such unified system for railroads. Instead, the railroads are wasting their and the government’s money on ten duplicative but not particularly compatible PTC systems that require very large numbers of expensive, high-maintenance and probably unreliable trackside sensors to monitor train position and speed. Since railroads regularly share trackage, this duplication is bizarre. Implementation of PTC has been delayed for years, at least in part because of the cost to complete it.

The WAZE/Google navigation system provides not only information on where roads go, which can be used for trip planning, it also monitors traffic to show what the most rapid route is likely to be. It does this by monitoring, through satellite communications, the behavior of vehicles using this navigation system to determine areas of road congestion or other problems.

Adapting this system to railroads would be relatively easy. WAZE/Google could substitute a map of the rail network for the road network and show the appropriate speed limit on all stretches of track as well as switch positions. This would be used to warn engineers if they are operating in a dangerous manner. In the event that an engineer ignores this warning, the receiver in the locomotive would automatically apply the train’s brakes.

As with the highway system, the positions and speeds all locomotives using the system, as determined using GPS, along with the positions of all switches in the system and the location of maintenance operations, could be sent through satellite to a central control where it would be monitored to determine a potential collision between trains.

There are roughly 27,000 locomotives, some thousands of additional trainsets not pulled by locomotives, and 140,000 miles of track in the U.S. The cost of installing equipment to send and receive signals, for navigation and for computer-based automatic braking, would be less than $5,000 per locomotive and per switch for a total of less than $300 million.

The cost of a real-time navigation system with some type of proximity warning and/or automatic braking system is less than $1,000 per motor vehicle. Software for adapting the highway navigation system to PTC and establishing a central control to warn of collisions would cost less than $100 million. Thus, an estimate of well under $1 billion for all of the PTC hardware and software to implement a new, navigation-based PTC system seems reasonable. This is considerably less than the cost of completing the current PTC systems and could be paid by a consortium of railroads. If the will were there, it should not take more than about a year to implement this new system.

A modern PTC could also become a basis for a more modern approach to railroad scheduling and management that could reduce costs and ensure more efficient use of the rail network. It could replace current antiquated and inefficient fixed-block signaling system. Because of industry competition and anti-trust considerations, it may require congressional action to  ensure national cooperation in establishing a unified 21st century PTC system.

The current approach to railroad safety is out of date and makes little sense. It lacks a rational connection with the reality of how most people are killed and injured in connection with railroads and the availability of effective technology. It results in ridiculous spending on what, at least in terms of human losses, is a relatively minor problem.

PTC based on the technologies used for road navigation could substantially reduce human, equipment, and other losses from collisions and derailments. These savings would be sufficient to pay for the 21st century system based on the Google navigation system. It would also be an excellent business opportunity for WAZE/Google. The fact that billions have already been invested in PTC is irrelevant to the question of how the railroads should proceed with PTC. It must abandon the current wasteful development and start with a fresh approach as outlined here.

Carl E. Nash was a Senior Executive in the National Highway Traffic Safety Administration. Since retirement, he has continued to conduct research and advocacy in transportation safety. Nash holds a Ph.D. in theoretical physics.

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