Yesterday, the all station Bedford service departing West Hampstead at 20:14 was cancelled just before 20:05 due to "a member of staff not being available". I suppose it was caused by driver shortage. The next all stations service was 30 minutes later. There were 2 other Bedford services in the meanwhile but one was cancelled and the other had St. Albans as the first stop. While I was annoyed at the short notice of the cancellation (would have tried another route if I knew in advance), I wonder why the current patten of service on Sunday is as it is (4 non-stop service between West Hampstead and St. Albans per hour, all stations service every 30 minutes). If there is a staff shortage, why not change to 4 all station services per hour? Is there any reason why this cannot be done? Is it because people living north of St. Albans would complain (as their services are now slower)?