If you have rail standards of the 21st century cellular is absolutely what you should be using for rail see: GSM-R . Apparently the DOT is even looking at this.
Now you’d need to build cellular infrastructure along your lines for that system. US rail owners are terminally uninterested in building or maintaining rail infrastructure so that’s not particularly likely to happen unless mandated.
The answer to a hyper-localized security issue isn’t attaching the equipment to an insecure network nor is it shifting to use insecure IoT type devices.
If you have rail standards of the 21st century cellular is absolutely what you should be using for rail see: GSM-R . Apparently the DOT is even looking at this.
Now you’d need to build cellular infrastructure along your lines for that system. US rail owners are terminally uninterested in building or maintaining rail infrastructure so that’s not particularly likely to happen unless mandated.