Stop distance

Welcome to



We want all members show that we are the professionals in the traffic so other look up to us.


You should learn this text properly so that you always think about it when driving a vehicle.

Learn how many meters you drive from finding a danger to your vehicle standing still.

No matter what type of vehicle we are going to handle, or how much experience we have, there are some important figures to keep in mind.

The reaction distance

Reaction distance is the distance you can travel from when you discovered the danger until you start to slow down or steering away).

The length of the reaction path is affected by.

Vehicle speed (proportional increase):
2 times higher speed = 2 times longer reaction distance.
5 times higher speed = 5 times longer reaction distance.

Your reaction time.
Usually 0.5–2 seconds.
45–54 year olds have the best response time in traffic.
18-24 year olds and those over 60 have the same reaction time in traffic. The young have sharper minds, but the elderly have more experience.

The reaction distance may be shorter if you can.

Predict dangers.
Readiness to act.

The reaction distance may be longer.

If you have to make choices (eg between braking or steering away).
Alcohol, drugs and medicines.

And it can disappear completely if you are not concentrated on the road.
Mobile phone.
CD player.
Children arguing in the car.

There are various methods to calculate the reaction distance.

But I show a simple method:

Calculate the reaction distance.

Delete the last digit of the speed, multiply by the reaction time and multiply by 3.

Example of calculation with speed 50 km / h and reaction time 1 second:

50 km / h ⇒ 5
5 x 1 x 3 = 15 meter reaction distance.

Braking distance.

Brake distance is the distance the car can be moved from the moment you start to brake until the car is stationary.

The braking distance is affected by

Vehicle speed (square increase; "raised to 2"):
2 times higher speed = 4 times longer braking distance.
3 times higher speed = 9 times longer braking distance.
The road (slope and roadway).
How heavy cargo you have.
The brakes (the condition of them, brake technology and the number of wheels that brake).

Calculate the braking distance

It is very difficult to make good calculations of the braking distance, because roadways and tire grips can be very different. The braking distance can for example be 10 times longer when it is slippery for example, wet of rain.

Prerequisites: Good and dry road, good tires and good brakes.

Formula: Delete the zero in the speed, multiply the number by itself and then multiply by 0.4.

0.4 comes from the fact that the braking distance from 10 km / h on dry road is about 0.4 meters. This has been calculated by researchers having measured the braking distance. Thus, in the simplified formula, one starts from the braking distance at 10 km / h and increases it square by increasing speed.

Example of calculation with speed 10 km / h:

10 km / h ⇒ 1
1 x 1 = 1
1 x 0.4 = 0.4 meter braking distance.

Example of calculation with speed 50 km / h:

50 km / h ⇒ 5
5 x 5 = 25
25 x 0.4 = 10 meter braking distance.

Example of calculation with speed 90 km / h:

90 km / h ⇒ 9
9 x 9 = 81
81 x 0.4 = 32 meter braking distance.

Stopping distance

Stop distance = reaction distance + braking distance.

Calculate the stopping distance with the easy methods.

It is summer and the road is dry. You drive at 90 km / h with a car that has good tires and good brakes. Suddenly you discover an obstacle on the road and slow down strongly. How long will the stop distance be, if your reaction time is 1 second?

The stopping distance is the reaction distance + the braking distance.

First, the reaction distance is counted:

90 km / h ⇒ 9
9 x 1 x* 3 = 27 meter reaction distance.

Then the braking distance is calculated:

90 km / h ⇒ 9
9 x 9 = 81
81 x 0.4 = 32 meter braking distance

Now the two routes are put together:

27 + 32 = 59 meters stopping distance.

So if you are completely concentrated on the road and the traffic, then it takes at least 59 meter 

to stop on a well-maintained vehicle that drives at 90 km/h, on a dry asphalt road.

This means that under these conditions you should have at least 60 meters to the vehicle in front of you, and with a safety margin I propose 100 meters.

A good and easy way to measure that you are at a safe distance from the vehicle in front of you is to start counting one thousand one, one thousand two, one thousand three, from the vehicle in front of you when he passing a particular point, until you arrive at the same point.

If you have been drinking alcohol or are tired. Or if you are engaged in mobile phones or something else in the car. Then you can count on an accident where you, your children or people in other cars or who are on or beside the road, may be badly injured or die.

And it's not so fun to live with the knowledge that your "important" facebook chat killed a child.

Driving a vehicle places high demands on the driver. We cannot just drive our own vehicle, we also have to drive all other vehicles at the same time.

If you are concentrated on your driving and keep track of other road users. Guess how they think and what they to do, so you can significantly lower your reaction time.

Copyright @ All Rights Reserved Gay MC Bikers Thailand