There's a verse I like a lot in Tao Te Jing: "One must know when it is enough. Those who know when it is enough will not perish." I think it's good to aim

There's a verse I like a lot in Tao Te Jing: "One must know when it is enough. Those who know when it is enough will not perish." I think it's good to aim for zero traffic deaths, as in many countries the situation is so bad that a lot of improvement is feasible. The long tail would definitely be much harder to tackle, but I don't expect this to be a serious problem in practice.