Interoperable Train Control (ITC) is a radio protocol operating at 220 MHz that is used by most railroads in the United States. ITC is a safety system designed to help prevent train-to-train collisions, derailments caused by excessive speed, incursions into work zones where maintenance crews are present, and movement of a train through a switch left in the wrong position. It runs in the background as a safety mechanism to apply the brakes if the crew makes a mistake.

Recently, Katso Juna wrote in to us to let us know that they have created a new program for Windows called "ITCMON:  Interoperable Train Control Monitoring software". Katso writes:

I will first address the obvious concerns: ITC/PTC is much safer than ATCS ever was. Due to the HMAC (Hashed Message Authentication Code) attached to every important message, it is not possible for anyone to spoof data without knowing a secret key.

Anyways, this first release runs on Windows (tested on Win 11) and needs an RTL-SDR, a 220mhz antenna, and the regular Windows Zadig RTL/USB drivers installed.

To make the most use of the software, you'll have to figure out the signal vs switch bits for each Wayside (not too hard), and also figure out where those Waysides are located to give them names. If its found to be useful then a next step might be to feed this data to a dispatcher type display. There is a lot of other interesting data that could be used.

So it seems that while the data messaging is encrypted, once you've matched the signal/switch bits for each wayside, you can still infer local train movements and activity from the wayside status beacons.

Katso has also mentioned that there is a groups.io page called PTCTalk where the program is being discussed.