You should be able to calculate the stopping distance
Important requirement: You can estimate the distance you need to go from a certain speed to a standstill. What I’m talking about is known in the trade as “stopping distance”. You should be able to calculate this as well as the so-called “braking distance” and “reaction distance”. So that your guardian angel doesn’t have to constantly work extra shifts.
According to the Federal Statistical Office, there are about 2.4 million traffic accidents on Germany’s roads. A frequent cause: underestimating one’s own reaction time and the actual braking distance until the final stop. Once learned in driving school, the calculation of braking, reaction, and stopping distances in everyday traffic suddenly degenerates into a great unknown. But as I will show you in a moment, it is not that difficult.
Stopping distance = reaction distance + braking distance
The stopping distance consists of the reaction distance and the braking distance. The decisive variable for calculating all three distances is literally always in the hands of the motorcyclist: speed.
1. the reaction distance: seeing, recognizing, and reacting takes time
The reaction time is the time it takes the driver to notice a threat and then apply the brake. If there are no medications, alcohol or other drugs involved, this usually takes a second. The metres that the driver covers at a certain speed during this time is the reaction distance. It is calculated by the following rule of thumb: Reaction distance = (speed ÷ 10) × 3. At a speed of 100 km/h the reaction distance alone is 30 metres.
Examples for the calculation of the reaction distance:
Speed in km/h
Reaction distance in metres
Note:
2. the braking distance: estimate when your vehicle will stop after the start of braking
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Formula for calculating the braking distance.
The braking distance is the distance travelled from the start of braking to the standstill of the vehicle. In other words: how many metres your motorcycle will travel while braking. Without reaction time or reaction distance (see above). The following formula has proven to be useful for calculating the braking distance: (Speed ÷ 10) × (Speed ÷ 10). At a speed of 100 km/h the braking distance is therefore a full 100 metres..
In the case of emergency braking, in which the brake and clutch are pressed simultaneously, the braking distance is reduced by half again each time. The formula must therefore be added: (speed ÷ 10) × (speed ÷ 10) ÷ 2. At our previous starting speed of 100 km/h, it takes 50 metres to stop your machine with an emergency stop.
Further examples for the calculation of the braking distance:
Speed in km/h
Braking distance “normal”
Braking distance “emergency”
As simple as the calculation sounds:
3. the stopping distance: the actual distance to get to a halt is decisive
The stopping distance is once again considerably longer than the braking distance. It begins when the danger is detected and ends when the vehicle comes to a halt. The stopping distance is therefore made up of points 1 and 2 – the reaction distance and the braking distance. I must therefore determine and add two partial values (reaction distance + braking distance) in order to calculate the required stopping distance.
Expressed in the formula: (speed ÷ 10) × (speed ÷ 10) + (speed ÷ 10 × 3). For my standard example at 100 km/h, the stopping distance under normal braking is 130 metres.
Further examples for the calculation of the stopping distance:
Speed in km/h
Stopping distance “normal”
stopping distance “emergency”
Important:
Decisive criteria for the length of the braking distance in addition to the speed:
- weather conditions
- Soil or road conditions
- Technical standard of the vehicle (e.g. ABS available)
- Condition of the brakes
- Brake actuation force
- tyre tread depth
- Condition of the driver (e.g. reaction time due to fatigue possibly higher than 1 second)
What else you should think about
Although motorcycles are lightweight compared to cars, their braking distance is usually slightly longer. This is partly due to the somewhat weaker brakes. On the other hand only two tyres have road traction. So the friction is lower and the braking effect is correspondingly weaker.
My advice
Just learn the required stopping distance for certain speed levels by heart using the formula and my examples. So you can make yourself aware of it in every situation. Apart from that: Drive with foresight and according to the conditions. If, for example, in fog the visibility is less than 50 metres and you notice obstacles and brake, you will not be able to stop in time at a speed of 60 km/h. And with the emergency braking that might save you, you risk your own fall or a rear-end collision in the rain.
More tips
Author of the article
Thorsten Rechtien
Competence Center
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Comments
Very nicely explained!
Espetially with a fluent English from inside Germany and up to date infos!
Very good. Thanks!
1) Braking distance depends on braking forces applied. If you ignore the braking force in your calculation, you are not doing a braking calculation.
2) People have used vehicle braking for 1,000 years, but it looks like they don’t know how to calculate braking distances correctly theoretically. To do it right, the key word is “friction”.
3) Reaction distance is unnecessary in braking calculation.
Also take into consideration the amount of grip the tires have on the road. The more the grip the less the breaking distance. So a huge breaking force applied + the friction between the tires and ground might result in a short breaking distance..
Thank you very much for presenting this data about the calculating the stopping distance, it’s known how to get approved but what are the next steps after getting the approval. Wonderful information, thanks a lot for sharing kind of content with us. Great post!
We are glad that you like our content. Thank you for your comment!
Many Greetings
Arianna Blittersdorf (TÜV Rheinland)
Here we get to know about the topic in clear and easy way. It helps us to decide that which one is best among its types. I enjoyed reading this article and would suggest others it as well. Thank you for this article! This is really very informative for us.
Thanks for the compliment!
Many greetings
Arianna Blittersdorf (TÜV Rheinland)
Thank you so much for the explanation. I have finally understood after numerous attempts.
We are glad if we could help you!
Many greetings
Arianna Blittersdorf (TÜV Rheinland)
It’s a great source of knowledge; I think it will be helpful for lot of people who are looking for learning more about the calculating stopping distance braking is not a matter of luck. Thank you very much for sharing this article.
Thanks for the compliment!
Best regards
Arianna Blittersdorf (TÜV Rheinland)
very noice
Do you also have reaction time and braking time related data or formulae?
Thank you very much for calculating stopping distance braking is not a matter of luck, it’s difficult for me to get such kind of information most of the time always… I really hope I can work on your tips and it works for me too, I am happy to come across your article.
(speed ÷ 10) × 3
As the formula above, why we need to divide by 10? 10 is stands for what? As for 3 also, is it meters or seconds?
I got a doubt regarding the formulas used here. The units of braking distance and reaction distance are meters, but they do not match the units of formulas used in it.
For example, the formula used for Braking distance is (Speed ÷ 10) × (Speed ÷ 10). The units of braking distance are meters whereas the units on the right-hand side of the Braking distance for (speed)^2/100 are m2/sec2. So, is there any derivation for that or is it simply calculated by using empirical formulas?
I hope you will provide the useful information: Thank you
In this post, the speed value is taken as km/hr and the result is given in metre… There is something wrong here. Kindly check and confirm.