I have also seen drivers use the middle doors when perhaps the safety element is questionable. Most drivers seem to use nearly all the time in the city centre but less so in the suburbs I find. I've seen a good few drivers use them on Aston Quay for example but not all get right up to the kerb as there's usually other buses blocking up the stop.
I actually can't win.
I try to do my best in reading who is getting off and where but no matter what people leave it till the bus is after filling with 40 or 50 and then decide oh I will get off here, say nothing and tend to bounce off the doors front or back.
There are occasions where if we open the rear doors people shoot on and make a run for the stairs.
With only 4 checkers for over a 1000 buses this is just too much put on each driver.
I don't know how many go ahead have but I'm really hoping it's more then 4 oh and 1 of those is in a car.....