OK, I've just discovered that there's a rail replacement scheduled for a day I'm due to fly into Gatwick.

Previously it had only been the Southern trains showing as cancelled and I was going to get the Great Western to Reading - but I digress....

Anyway, just how bad will this be? Should I be making alternative arrangements to get somewhere like Reigate, or will the bus service be running efficiently? The timetable suggests 4 buses an hour to Redhill, which I think for a Sunday lunchtime will be wholly inadequate.