I just booked a flight from IAD to Cologne with UA. When we started the UA rep reminded me that it was an ICE train from FRA to Cologne Hbf.

Has anyone ever done this? Is the train ticket a standard fare or special fare that is exclusive for that time only. My question is if I am ready to go early can I jump on an earlier train. .bomb is showing it as a W fare. Also I assume no miles for the train, but .bomb show a LH flight number and a train seat map. Any advice would help.