"David B" wrote in message
...
Each individual driver is running to a timetable he/she has which gives
precise times to pass certain points - the duty card. The inspectors book
also has these times. Timetables are necessary to prevent 'bunching' so
buses do actually come say, every 5 minutes instead of 6 buses in a row,
then nothing for half an hour. Of course due to traffic and other things
this seems to happen anyway 
ok, and thats fair enough. but surely theres something wrong with their
cards or the way that thy follow them if they gain so many minutes that they
have to stop for five at one single stop? surely the cards woulda made them
stop a minute or so over the past few stops?