Both teams are from Up North (it's Leeds Rhinos v Warrington Wolves), so travel is ideally suited to supporters who want to Park & Ride using the services of Chiltern Railways.
Nearly every station between Princes Risborough and South Ruislip has been buzzing with rugby supporters all morning.
Extra trains have been laid on, they are longer than usual, yet still packed.
It's a gloriously sunny day, so a great time should be had by all.
Obviously, by the end of the afternoon, some travelers will be happier than others.