没有
There are no solutions. There are only trade-offs.
Pedestrians never seem to realize that they are a threat to the safety of cars.
Virtually no idea is too ridiculous to be accepted, even by very intelligent and highly educated people, if it provides a way for them to feel special and important. Some confuse that feeling with idealism.
The first lesson of economics is scarcity: There is never enough of anything to satisfy all those who want it. The first lesson of politics is to disregard the first lesson of economics.