On Aug 18, 2017 I took the 321 CHI-STL. (This was the Friday before the eclipse.) Something (a truck at a grade crossing, I think) took down a power line onto the tracks and we stopped for about an hour at Alton. The crew said the power line was about 10 miles south, that they could have proceeded to about a mile before it and waited there, but they chose to wait at the Alton station so we could get out and walk around. When we left, they said they would proceed at normal speed until we got close to the site, then go very slowly past the repair crews, and eventually speed up to normal speed so we might be another half hour late arriving in St Louis. What actually happened is we went quickly for the first 5 miles or so, then very slowly until we were within sight of St Louis, before we finally sped up again. We got there about 2 1/2 to 3 hours late and I missed dinner with my eclipse tour group.
I don't think there was a signalling problem, didn't notice any issues at grade crossings, we didn't stop, just went very very slowly (about 10 mph tops) for about 15-20 miles. Maybe there was freight or commuter congestion due to the track being out of service. (I don't remember if it was a single or double track, but if it was double, I think both tracks would have been out while they removed the wire.
Just noticed, looking at the schedule, it's only 27 miles from Alton to St Louis, but they allow an hour and one minute. Then there's another 34 minutes (is this where they drop the 321 coach?) before leaving. No wonder people get annoyed at the TE!