Speeding vs stopping distance - defensive driving

Written by Ronak Shah

Speeding is the biggest contributing factor in road accidents and majority of drivers on our roads have no idea of the true effect that speeding has if something were to go wrong. The fact is even travelling at an additional 10km/h over the speed limit could result in 2 very different outcomes if something were to happen.

Imagine you were driving along at 60km/h and another vehicle pulled out immediately in front of you from a side street you needed to stop immediately to avoid having an accident. If you had the correct emergency braking technique, on average, you would pull up in approximately 3 car lengths without including the reaction time component. If you were then to double your speed to 120km/h in a 110km/h zone on a freeway, which many drivers don’t think twice about, and were faced by a similar situation and needed to stop suddenly, how many car lengths do you think it would take to stop? Come up with the amount of car lengths in your head and then watch the video below.

***  View the Video ***

I am sure you are very shocked and surprised by the dramatic difference in stopping distances between 60km/h and 120km/h and may be struggling to work out how it can be so much greater! Essentially when you are driving along your car is a big ball of kinetic energy which the brakes then disperse as heat as you slow down.  The amount of energy behind the vehicle is a combination of the mass of the vehicle combined with the speed you are travelling. If you double your mass, at the same speed, you will double your stopping distance however the speed component is actually has an exponential relationship to stopping distance and that is why even with a small amount of extra speed your stopping distance is greatly increased.

The above video and examples also don’t take into account reaction time, which is on average 1.5 seconds. At 120km/h you can add on an additional 50 metres to your stopping distance just for reaction time! The scary part however is the impact side of things, if you were to impact something at 120km/h vs 60km/h the impact would also be dramatically greater exactly the same as the stopping distance.

ANCAP Safety Ratings are tested at 40mph (64km/h) for front on impacts and approximately 40km/h for side impact crashes as if you impact at a higher speed they deem you have an unlikely chance of surviving as the impact will be dramatically greater, just like the stopping distance. It is therefore important to have the skills needed to perform an emergency stop , which was performed in the video, to give yourself the best chance of getting under 64km/h and to a safe speed if faced by an emergency situation behind the wheel. 

This is one of the many skills we teach at Academy of Road Safety to ensure drivers know what to do if faced by an emergency situation on the road and how to drive as low risk as possible to ensure drivers have the best chance of keeping themselves, and their loved ones, safe on the road. We are currently running a promotion on our Driver Safety Program – Level 1 course. This is a half day defensive driving program where you will get to learn the skills of emergency braking within a controlled environment with tuition from expert instructors, along with strategies to dramatically lower your chance of being involved in an accident.

We hold the Driver Safety Program at Sydney International Regatta Centre in Penrith and have a special offer currently on our Level 1 courses. The course is normally $199 however you can now attend the course half price at $99! This offer applies to the upcoming courses on Sunday 24th May and Saturday 25th July 2015. To claim this special offer enter the discount code ‘OROAD500215’ when booking online at www.academyofroadsafety.com.au  or quote the code over the phone on (02) 9863 7999.

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