Specific pet peeve of mine for the transit in my city is building a Bus Rapid Transit line right along the path of an already existing network of rail lines which are under-utilized by the rail company, at a cost comparable to building a whole new LRT line, through an area of the city which used to be empty marshland that was conveniently purchased and started development by a friend of the mayor when the BRT line did rather than along one of the actual main corridors of the city, to a part of a the city that was already the best serviced by existing transit rather than one of the parts that are impossible to navigate without a car, in a city where we get a huge amount of annual snowfall and have a ridiculous deficit of road maintenance already (BRT route being another road that has to be plowed and maintained vs trains where u kinda can just put a plow on the front), while you are constantly litigating with the transit driver union and refuse to pay even close to an acceptable wage while simultaneously complaining that pre-covid service cannot be restored due to lack of drivers, and then proceeding to mostly abandon or stall any of the other proposed transit expansion in the city for almost a decade.

Outside of that specific example it really bothers me when people stand directly in front of the doors of a subway or tram car waiting to get on. Not only is it stupid and illogical if you want to actually get on the train but everywhere has ample arrows and signs indicating where you should stand to wait to get on so as to allow other people off.