Here's one that I have: Bicycles shouldn't be on the road.
The physics of the situation are terrible. Cars have far too much momentum, and bikes have far too little. On city roads, drivers are operating under a fender-bender risk assumption, whereas cyclists are operating under a violent death risk assumption. Where cars are driving fast, bikes are driving slow, and where cars are driving slow, bikes are often driving fast. Also, bikes follow some, but not all rules that cars follow.
These mismatches lead to a very dangerous situation for cyclists which cannot be overcome by drivers simply being mindful.
Cities should either redesign roads to give cyclists a far greater safety buffer, or cyclists should ride on sidewalks and bike paths.