I recently had a buggy on my bus that was so wide it would not go past my cab on its wheels - it had to be carried sideways by Mum & Dad to the designated area!
I agree with your comments on multiple shopping bags attached to the handles of the buggy, which can outweigh the toddler in the seat. Guess who gets shouted at when gravity takes effect - the bus driver.
I simply explain that it is their responsability to look after their children in transit - not mine. I have enough to be getting on with thank you.
Apparently, most baby buggy makers supply a set of guidelines in terms of using them on public transport, which includes getting off the bus backwards, i.e. mother first buggy last. In practice, I rarely see this happen.
What also gets to me is the conflict that can happen between senior citizens who wish to sit in the seats with their shopping trolleys, who will not then make allowances for baby buggies, when there are plenty of free seats further back in the bus.
At the end of the day, Senior Citizens can travel for free as many times as they want, virtually all day, every day - and go as far as they want as well - the world is their oyster. Thank you Tony Blair :!
The Mum (or Dad) with the buggy is generally a fare paying passenger, and, in the event of a dispute over seats, in my world, they would have priority, and thats how I deal with it to be honest.
Most buses can accomodate 3 small buggies, or 2 big ones - thats it. Sometimes you pull up at a stop and there are 3 or more buggies there and you think to yourself " oh crap" because you can't let all of them on, but we are regulated by H&S just like anyone else, and the aisle of the but cannot be blocked by excess buggies for escape reasons in the event of an accident, or bus catching on fire for example.
Rant over - hope this explains things a little