Recently, because of the improvement of road condition and the performance of the vehicle, the average velocity of modern vehicle could reach to the two times than before on the road which condition is very well, this means in the same braking condition、the same time, the arrester of the modern vehicle would produce more caloric and undertake more caloric burthen;when the vehicle run on the road of mountainous area and mine, it will often go long slope, in order not to accelerate the speed to t...