 Have you ever noticed that cars take longer to stop when they're travelling faster or when it's raining? In this video we will be looking at what affects stopping distance and why understanding them is so important to our safety. Stopping distance is how far a car moves between the driver noticing something in front of them and the car coming to a stop. It's affected by two main factors, thinking distance and braking distance. Since distance equals speed by time, thinking distance is the time that it takes for the driver to react, multiplied by the speed the vehicle is moving at. There are lots of factors which affect thinking distance, for example tiredness, being intoxicated and distractions such as using your phone or playing loud music. This is because they all slow down your reactions, meaning it takes longer for you to realise what is going on and then press the brake pedal. The speed of the car also affects thinking distance. Although the speed won't make any difference to the time it takes to react, you will go further in that time. At motorway speed, you could cover the length of four cars before you even apply the brakes. Braking distance is how far the car travels once you've put your foot on the brake. The faster you're driving or the heavier your vehicle is, increases the braking distance. Faster or heavier vehicles have a larger kinetic energy which needs to be lost before the car comes to a stop. Braking distance is also affected by the road's conditions like ice and rain or wet leaves on the road and the condition of the car. Are the brakes good? Do the tyres have good grip? And how many people are in the car? These all reduce the car's grip, making it longer to decelerate. The total stopping distance is the thinking distance and braking distance added together. We can draw total stopping distance on a graph like this. As always, time is on the x-axis and velocity is on the y-axis. We can find the thinking and stopping distances from the areas. See how the speed does not change during the thinking time which lasts for two seconds. So we've seen that thinking distances are affected by human factors and braking distances by things like speed, weather and load. But why is it important to understand stopping distances? Well, the distance taken to stop increases hugely as the speed goes up. 32 km per hour will take about 12 metres to stop on dry roads. So you'd think then that double the speed to 64 km per hour, the stopping distance would also double to 24 metres. But no, it's much more. It actually takes on average 36 metres, three times what it would have at 32 km per hour and 96 km per hour, so triple the speed actually takes 73 metres, that's 18 car lengths, much more than triple the distance. This is why it's really, really important to leave a large gap between you and the car in front at high speeds. A small increase in speed will take an extra 20 metres to stop. So in this video you should have learnt that the stopping distance is the distance a vehicle travels between the driver spotting an obstruction on the road and the car's speed dropping to 0 metres per second. The stopping distance is made up of the thinking distance and the braking distance and the factors that affect them. If you liked the video, give it a thumbs up and don't forget to subscribe, comment below if you have any questions. Why not check out our Fusequal app as well. Until next time.