It wasn't long after ETMS PTC systems had been commissioned that the railroads using the older IIATS system went on a tear to decommission the old upside-down canoes. Most notably affected were the CNW-North and Northwest commuter lines operated by METRA, large parts of the ATSF Transcon in Arizona and Missouri and the Amtrak Surfliner route between Fullerton and San Diego. Apart of the NJT RiverLINE, which uses the IIATS shoes as a magnetic trip stop, the last main line use of IIATS is on Amtrak's Southwest Chief route between Albuquerque, NM and La Junta, CO.
Since BNSF yeeted IIATS off its main lines in 2021, the status of ATS on the Raton Pass route has been somewhat "indeterminate". IIATS had been in service on New Mexico Passenger Rail Authority owned track between Albuquerque and Lamy, NM and as of 2025 the shoes were still in place minus some contraction at the southern end of the territory. Fixed IIATS shoes were also present on the BNSF owned Glorieta Sub to protect specific curves with full ATS territory present on the Raton Sub between Trinidad and La Junta, CO. Imagery shows that the BNSF territory IIATS shoes were also still in place as of 2025.
One might recognize the Raton Pass route as hosting the dwindling number of main line semaphore signals as well as the last main line Wig Wag. That is because the only regular traffic on this stretch of track is Amtrak's daily Sunset passenger train. As a result the route is both PTC exempt and at the absolute bottom of BNSF's priority for capital improvements or even basic maintenance. So while the ATS inductors were still in place it was plausible that the requirement for its operation had been removed along with the rest of the Chief route. Fast forward to 2026 when I noticed this Amtrak delay report for May 12th's westbound Southwest Chief.
3(12) with engines 167 and 14 with 225 customers onboard was delayed departing Chicago Union Station account mechanical was working on loading issues with engine 14. 3 departed Chicago 17 minutes late at 14:42. 3 was further delayed account being stuck in penalty on M1 at CP Roosevelt just outside the station. Mechanical responded to the train, the train maintained HEP. Mechanical initially resolved the issue and the train departed but was soon stopped again in penalty. Mechanical then bad ordered engine 167 and instructed the train to shove back to Union Station. Mechanical responded to the station to replace the ATS shoe on engine 167. The train departed Chicago a 2nd time after an additional 1 hour and 57 minute delay.
So yes, IIATS is still in service on the Raton Pass route and leading locomotives on Amtrak's Trains 3 and 4 are required to have ATS equipment. A quick check has shown that the new ALC-42 Chargers do not lead on the Chief for this very reason (they were not built with such an old school protection system). Unfortunately Amtrak has filed a petition with the FRA to discontinue the system at least on the BNSF Subdivisions. The reason cited is a lack of 90mph running as opposed to the more typical PTC replacement excuse.
Even when the petition is granted it is unclear if BNSF will bother removing the inductors or clipping wires in the signal cabinets since they don't really get in the way. It is also unclear if the NMPRA (RailRunner) will retire its ATS system at the same time or if that system is even used by anything other than Amtrak trains 3 and 4.
One final mystery is what happened to the IIATS system on the Raton and La Junta subs in the mid 2000's. In that time speeds on both subdivisions dropped from 90mph to 79mph (the non-ATS equipped national rail speed limit). However all or part of that ATS territory was still in place up to and including the present day (2026). If the track class was downgraded from 5 to 4, it's plausible that use of 79mph instead of 80mph is just a reflexive tic for the BNSF rules department. However I had also been informed that ATS had been "taken out of service" on these line segments despite the fact the timetables had ATS in service. If anyone knows please leave a comment, but if I had to guess BNSF may have started skipping some testing requirement necessary for the speeds greater than 80.
