Having to dodge bikers when walking down the sidewalk. Where I live it seems to be commonly accepted to bike on sidewalks and the excuse I have heard the most is that they do it because the bike roads are sometimes made of cobblestone which is hard to ride a bike on. So you choose to ride a bike, but you will put others' safety at stake because you don't feel safe on your designated lane? I wouldn't even mind if they did it carefully, slowing down when nearing and/or passing by a pedestrian, but these people more often than not go full speed and don't look out for pedestrians at all. Every day when I'm walking to work I have to be on the lookout for bikes flying by to prevent getting bumped into. It's mostly how they act like they're in the right and everyone has to step aside for them even though they are on the wrong lane.. ugh
*end of rant*
Wait, is it about Berlin or Netherlands? Because I've never saw anyone biking on sidewalks during my 10-days stay in Rotterdam. Everyone used the bike roads.
I frequently bike to work from April to end of October if weather is alright (did that today too), and as there are no designated bike roads (we have them in the center of our city and in the parks, and everyone ignores the latter ones), I usually use the actual road for cars. However, sometimes it's just not really safe to use the car roads - we have a speed limit of 60 kmph, except you get the ticket only if you went over 80 kmph, 60-80 is just a verbal warning and no one cares about that so effectively the speed limit is 80 kmph.
So, well, sometimes I have to use the sidewalks, but I never go faster than the pedestrians if I don't have enough room to pass. I'll get off the bike if necessary. I've never used the, uh, bicycle bell (is that how it's called?) in three years of using those rental bikes. That's just idiotic. I'm on the road for pedestrians, I'm a guest here, I have to accommodate to them, not the other way around. However, about 8 cyclists out of 10 do what you just described. So people just lump every cyclist on the sidewalk in the 'asshole' category.
Also, the 'cobblestones' excuse? Not safe? That's utter bullshit. Not comfortable, yeah, sure, but that's it. They should see the roads' condition here in Moscow.