Dangerous difference of speed危險的速差

Many motorcyclists like running across inner lane when turning left.
They think they can cut in as long as they are faster.
Actually it is a dangerous behavior.
For example, if you want to run across by 60 degrees;
70 x sin(60) = 60.2;
you should run more than 70km/h to cut in a car at 60km/h.
Look at the motorcycle in front of me,
I have to brake my car to avoid hitting him.
很多機車騎士很喜歡在左轉時切過內側車道,
以為自己只要比別人快就可以超過去,
實際上這是非常危險的行為.
舉例來說, 要以60度角切過車道,
70 x sin(60) = 60.2,
因此機車要以約時速70公里才可以切過時速60公里的直行車.
看看我前面的機車, 我必須要煞車才不會撞上他.