PTC Information

By , March 28, 2013

PTC Background

Positive train control (PTC) is a system of functional requirements for monitoring and controlling train movements to provide increased safety.  The Rail Safety Improvement Act of 2008 as enacted by Congress requires all Class I railroads and passenger rail operators to implement a mandatory PTC collision avoidance system by December 31st 2015. The technology must be installed on all main-line track where intercity passenger railroads and commuter railroads operate, as well as freight lines.


Existing safety systems use spaced, track-side equipment to determine train location within a block of track, and a relatively simplistic colored-light notification system for drivers. 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. For most railroads, the planned wireless infrastructure for PTC will use a single frequency-band near 220 MHz. PTC will be inherently more reliable, and offer greater real-time functionality than conventional systems.


For more information on PTC please see Jim Bakers white paper. The PTC_White Paper outlines the regulatory history and technical architecture of PTC, and reviews the activities of key players including railroads and equipment vendors.


PTC-220 Waivers

PTC-220 (a freight rail consortium that has purchased significant spectrum around 220 MHz) has recently submitted to the FCC a request for waiver of a couple of FCC rules that will ensure the efficient operation of PTC in the 220 MHz band. PTC-220 believes that these waivers are necessary to get the full benefit of the spectrum they own, and will maximize the amount of spectrum that can be made available to other PTC operators.


Pertinent documents