METRO Magazine Logo
MenuMENU
SearchSEARCH

Positive Train Control Promotes Track Safety

The Illinois DOT PTC project is part of a larger effort to make trains safer.

by Leslie Davis, managing editor
July 1, 2001
5 min to read


Reducing the probability of collisions between trains, collisions between trains and maintenance-of-way crews and overspeed accidents are top priorities for any rail operation. The Illinois Department of Transportation (IDOT), in conjunction with the Federal Railroad Administration (FRA) and Association of American Railroads (AAR), is working on a way to make those incidents more preventable with its positive train control (PTC) project. The project entails installing a PTC system on a 120-mile segment of a mixed passenger/freight line of the Union Pacific Railroad extending between Springfield and Mazonia, Ill. The line segment is part of a high-speed rail corridor designated by IDOT and the FRA between Chicago and St. Louis. “The primary benefit is increased railway safety,” says Alan Polivka, general manager of the North American Joint Positive Train Control Program, which the IDOT project is part of. “The project is going very well, with great momentum.” On half of the segment, the system is being integrated with the existing railroad traffic control and signaling system. There, the system operates in fixed block mode. Existing signals allow for speeds of up to 79 mph; the PTC system allows for speeds of above 79 mph. The system is being designed so that the authority conveyed by the onboard display is constrained by the wayside signal system in this half of the segment. The other half of the segment uses the PTC as a stand-alone system with moving block operation. It can provide conventional fixed block operation for trains not equipped with PTC onboard functionality, or for which digital data radio communications have been lost. These non-communicating trains will be tracked by track block occupancy status to the office via the data communications network. PTC involves the application of digital data communications, automatic positioning systems, wayside interface units, onboard and control center computers and other advanced technologies. The IDOT project is now halfway through its 30-month development that will be complete at the end of 2002, with revenue operation slated for 2003. The design is being implemented in multiple phases, with each phase adding functions that could stand alone. The primary use for this type of system is on high-speed passenger lines and freight lines, though other types of rail operations can use it. Two keys to the performance of the system are: the ability to locate and monitor movement of trains with precision and the ability of the operators to safely and effectively use the system. Both are being done within the project’s objectives of being cost-effective. For each part of the system built, extensive testing is done before being deployed on the IDOT corridor. Field testing of each build is also performed. The IDOT PTC territory contains 133 crossings — 103 public road crossings, 10 pedestrian crossings and 20 private at-grade crossings. Of those, 94 are equipped with automatic warning systems and many were upgraded to use constant time warning equipment. As part of the project, 74 crossings will be upgraded with advanced activation capabilities to provide for high-speed passenger operation. The system developer/integrator for the IDOT project is a team led by Lockheed Martin Corp. and includes Wabtec Railway Electronics, Union Switch & Signal Inc. and Parsons Brinckerhoff Transit & Rail Systems Inc. The prime contractor for the project is the Transportation Technology Center Inc. Goals of IDOT project The IDOT PTC system will function as a safety-critical train control system independently and in conjunction with the existing Union Pacific CTC system used to control the territory. Several things imperative to the project are: 1. Displaying operating information to rail crews. The IDOT PTC system will continuously display train location, limits of authority, actual train speed, maximum authorized speed and bulletin information. 2. Warning train crews of potential violations. The system will warn of approach to authority limits or reduction in authorized speed. 3. Open standards. The system is being designed to conform with or set new open industry standards, allowing interoperability of trains among different railroads and cost-effective availability of products from multiple vendors. 4. Demonstrate moving block operation. The system will provide moving block operations in PTC stand-alone territory, allowing communicating trains authority to the rear of preceding communicating trains rather than to fixed block limits. 5. Integrating speed limits and restrictions. The system will integrate temporary and permanent restrictions on train movement to determine the most restrictive operation allowed. Other PTC projects The IDOT project is part of the North American Joint Positive Train Control Program (NAJPTC), a five-year, $60 million effort sponsored and funded by the AAR, the FRA and IDOT. The purpose of the program is to develop standards for PTC system components to promote industry interoperability. The NAJPTC consists of three inter-related projects: the IDOT PTC Project, the Eastern PTC Project and the Industry Train Control Standards Project. The projects provide input to and accept outputs from each other as they work toward interoperability. The Industry Train Control Standards Project is developing industry-wide train control standards for cost-effective, interoperable train control and related systems and devices. The project published standards, including the Train Control Standards Data Dictionary that provides a common, core set of data elements to be used in the development of a standard system. The Eastern PTC Project has defined an interoperable onboard platform and is developing a standard approach for integrating it with various types of train control territories. This project already presented an onboard platform prototype and is now working on integrating that with existing wayside train control systems.

Topics:Rail
Subscribe to Our Newsletter

More Rail

A fleet of Caltrain electrified trains on tracks
Railby StaffApril 3, 2026

Funding Gap Could Force Caltrain to Slash Service, Close Stations

The Peninsula Corridor Joint Powers Board recently met for a budget workshop, during which staff outlined the significant service reductions Caltrain could be forced to make without new external funding. 

Read More →
SEPTA's Exo railcars
Railby StaffApril 2, 2026

SEPTA Purchases Montreal Coach Cars to Bolster Regional Rail Fleet

Funding for the purchase of the railcars comes from the nearly $220 million in additional capital dollars Gov. Josh Shapiro allocated in November 2025 to support urgent safety upgrades and infrastructure improvements.

Read More →
The South Shore Line with Passengers
Railby StaffApril 1, 2026

South Shore Line Extension Debuts, Boosting Rail Access in Northwest Indiana

The $945 million project connects four new stations and expands regional mobility.

Read More →
Ad Loading...
A rendering of a California High-Speed Rail vehicle
Railby StaffApril 1, 2026

High-Speed Rail May Boost Brain Health, New Study Finds

Research ties rail access to lower depression, better cognition and improved air quality.

Read More →
An MBTA commuter rail at a station.
Railby StaffMarch 31, 2026

Massachusetts Announces Summer Savings for Commuter Rail Riders

With major events and increased travel expected across the state this summer, the Administration is focused on making sure people have a reliable, affordable alternative to driving so we can reduce congestion, support daily commuters, and keep Massachusetts moving.

Read More →
A Sound Transit Crosslake Connection Link light rail vehicle
Railby StaffMarch 30, 2026

Sound Transit Opens Crosslake Connection, Completing Link 2 Line

The final seven-mile segment of the 2 Line includes new stations at Mercer Island and Judkins Park and connects to the 1 Line at the International District/Chinatown Station. The Link light rail system now spans 63 miles and includes 50 stations.

Read More →
Ad Loading...
SEPTA M vehicle on bridge
Railby StaffMarch 30, 2026

SEPTA Set to Begin Major Rehabilitation Project Along M Line

From March 29 through May 9, shuttle buses will replace train service between Bridgeport Station and Norristown Transit Center. Train service will operate as normal between Bridgeport Station and 69th Street Transit Center.

Read More →
Supervisor and LA Metro Board Member Lindsey P. Horvath stands at a podium with a crowd of community members behind her.
Railby Staff and News ReportsMarch 27, 2026

LA Metro Board Advances K Line Northern Extension Through Fairfax and West Hollywood

The project will create the first continuous north-south rail line in the LA basin, connecting major job centers, transit lines, and communities.

Read More →
Nadine S. Lee
Managementby StaffMarch 26, 2026

DART's President/CEO Announces Departure from Agency

Nadine S. Lee, who has served as president/CEO since July 2021, said the decision comes after careful reflection on the agency’s progress and its path forward.

Read More →
Ad Loading...
A Houston automated people mover manufactured by Alstom.
Technologyby Staff and News ReportsMarch 26, 2026

Biz Briefs: Alstom in Houston, DATTCO Makes Acquisition, and More

In this edition of Biz Briefs, we highlight the latest developments shaping the future of mobility — from manufacturers and technology providers to transit agencies and motorcoach service operators.

Read More →