Yeah, I'm going to add a disclaimer about this. I've been watching the GO trains from my window this morning and they lag about a minute behind. My site grabs data on a minute interval, and I know some of the API's say they purposefully add GPS lag.

I've made something similar in the past and my experience with the specific API was that it was surprisingly well considered but the actual data it returned was unreliable at best. Not just "slightly obfuscated for paranoid physical security reasons" but actually missing trains and reporting incorrect names.

For Amtrak only you can use the official source https://www.amtrak.com/track-your-train.html too (it shows route and also delay)