All these crashes turn up because cars are moving at the highest speed, but with small distance from each other. Overtaking, you should always take into consideration that the overtaken vehicle can suddenly swerve, avoid a dent, shift to the left, just relaxing and not noticing your presence, brake hard and move to the left, to turn down narrow clearing.
It is known that the safest speed is the flow velocity. Driving slowly, you make other drivers to overtake you. It's a difficult maneuver, entailing risk of the road traffic accident. In the same way, if you pick-up the speed, you have to constantly overtake other drivers.
Test to determine the reaction speed
Take a strip of cardboard 4,7-inch long, 1,1-inch wide and have someone hold it so that the lower end is between divorced thumb and forefinger of your right hand. The person who holds the strip, should suddenly have to let it go, and you need to catch it. We do not have time - then with the speed of response you're out of luck. However, you can compensate for this by the ability to predict danger in advance and clearly fulfilled driving skills in critical situations.