Huh. I'm Irish; it would never occur to me to try this. Buses will sometimes delay departure if someone is visibly running for the stop, but that's as far as it goes.
I think maybe France might be an outlier there. Honestly, opening the door in random places seems kind of unsafe.
EDIT: As people are doing stories of public transport in different countries, here's mine. I was getting the BART in San Francisco carrying luggage. The driver _leaned out the window_ to warn me that this one wasn't going to the airport. As it happened, that was what I was going for; I was going elsewhere and then on to the airport later. But it was nice of her to check (and very unusual; don't think I've been anywhere else where train drivers interact with the public at all). Always think about that when I hear people complaining about San Francisco.
A German woman told me about her trip to Ireland: She tried to buy a bus ticket from the driver, like she did at home. But, in Ireland, you have to buy it at the station. The driver pulled up next to the station and said, “Run in there and buy you ticket quick! I’ll wait for you.” She did it in complete disbelief. “This would never happen in Germany!”, she said.