Western Railroad Discussion > Positive Train Control Question

The development of GPS-based certified navigation services for the aviation industry is a very complex business, and it is by no means finished:

http://gps.faa.gov/FAQ/index.htm

What augumentation systems will railways use to ensure reliability of the GPS measurements, and as backup in the event that the GPS locationing in PTC systems is degraded or lost for one reason or another? Will track circuit detection systems still be the main provider of track occupancy data for safety purposes?

Ray

Remember that huge wreck up in Washington years back the closed I-5 south of Kalama?
BNSF and UP were testing the PTS in earnest after that and then it just kind of faded away, same with Electronic AirBrakes, the technology exists but nobody wants to pay for it.
Things that make you go hmmm.


TCSmith

There was extensive testing of PTS on BNSF/UP beginning in 1994 and running up through 1997 in the Pacific Northwest. The testing culminated when the PTS technology was used to successfully stop a train as it approached the end of its authority limit. Generally the results were encouraging, but there are still many issues yet to be resolved before such a system is considered failsafe. We have taken the specs, "lessons learned" and our results and sent them to the high-speed rail Chicago-St. Louis project headed by the Illinois DOT for testing. The aim of the new tests is to make the technology compatible between all railroads, as well as Amtrak. That effort should begin later this year and extend into next year. At this point there is no PTS "on the shelf".