The simple truth about speeding is: the faster you go, the longer it takes to stop and, if you crash, the harder the impact.
Reaction distance is the distance you travel between seeing a problem and hitting the brakes. If you’re on the ball (i.e. not distracted), you’ll react in 1.5 seconds. That is pretty quick. But despite your quick reaction, if you’re doing 60km/h, you’ll still travel 25 metres in the time it takes for the message to get from your brain to your foot.
Braking distance is the number of metres you travel between hitting the brakes and coming to a complete stop. You’ll cover another 20 metres before this happens, assuming you’re driving on a dry road, in a modern car with good tyres and brakes. If the road is wet, or your car is a bit dodgy, things can get very scary.
Stopping distance is the distance you get when you add your reaction distance to your braking distance. If you’re doing 60km/h, add 25 metres (best case reaction distance) to 20 metres (best case braking distance), and you should come with 45 metres. For the sports-minded, that’s the length of two cricket pitches.
Now taking this information into consideration, what happens if you are speeding? It is easy to see that 5km/hr over the speed limit, even in ideal conditions, will greatly impact your ability to brake in time to avoid a crash. The stopping distance due to speeding could be the difference between someone escaping with little more than a scare and a pedestrian losing their life.