How do you work out stopping distance, thinking distance and braking distance and why is it so important? In the UK, tailgating, that is driving too closely to the vehicle in front, is a top cause of accidents. It should be noted that not only is it a dangerous thing to do, it is also illegal. If the driver suddenly brakes, the tailgating driver has little time to react and is therefore running the risk of a collision. As we head into winter and the wet and icy roads often associated with the season, K&M Tyres, located in Crowborough, East Sussex is looking at this topic in more detail to keep you safer on the roads. We look at the definitions of stopping distance, thinking distance and braking distance, tailgating and the two-second rule and factors affecting your overall stopping distance.
Tailgating and the two-second rule
National Highways reports that, ‘Tailgating is a factor in one in eight collisions on the strategic road network.’ It goes on to add that this illegal action is the biggest bugbear that drivers have about other motorway users. Almost nine out of ten drivers say they have experienced or witnessed it. The Highway Code tells drivers to allow at least a two-second gap between you and the vehicle in front on roads carrying faster-moving traffic and in tunnels where visibility is reduced. This gap should be wider as speeds increase. Furthermore, the gap should be at least doubled on wet roads and increased still further on icy roads.
Definitions of distances:
Stopping distance – the total distance you travel before you apply the brakes, plus the distance you travel while the brakes slow you down.
Thinking distance – the distance travelled between the time that you realise you need to brake, and the time it takes to activate the brakes. This is approximately one foot for every mph you are travelling at, so for example, travelling at 20mph, your thinking distance is about 20 feet.
Braking distance – the distance your car travels after you have applied the brakes until your vehicle comes to a stop.
Stopping distance
There is a formula to work out the stopping distance. If you start at 20mph, you multiply the speed by intervals of 0.5 beginning with 2 (2.5, 3, 3.5, 4, 4.5 etc.) However, these are only approximate distances.
20 mph x 2 = 40 feet (12 meters or 3 car lengths)
30 mph x 2.5 = 75 feet (23 meters or 6 car lengths)
40 mph x 3 = 120 feet (36.5 meters or 9 car lengths)
50 mph x 3.5 = 175 feet (53 meters or 13 car lengths)
60 mph x 4 = 240 feet (73 meters or 18 car lengths)
70 mph x 4.5 = 315 feet (96 meters or 24 car lengths)
Factors affecting your overall stopping distance
- Speed you are travelling at – the higher the speed, the more time for braking
- Road – level, uphill or downhill and the gradient
- Weather – sunny, windy, dry, wet or icy
- Tyres – condition, inflation level, tread depth
- https://www.kandmcitroen.com/regularly-check-brakes-listen-noises/Brakes – fully serviced and working well
- You – health, medication, tired, distractions, alcohol or drugs
How can K&M Tyres help you prepare your vehicle for winter driving?
We want you to have the best chance of stopping in time and that means knowing your braking distance. You must also have a set of tyres that are in good condition. They should have enough tread, be inflated to the correct pressure and have no bulges or splits. Also ensure that your brakes are in good working order. Here at K&M Tyres, an independent tyre and car maintenance service centre and Castrol SERVICE workshop in Crowborough, East Sussex, we offer a FREE tyre check. We also have a wide selection of winter tyres, to keep you safer on wet and icy roads. Call us on 01892 653131 to book your vehicle in.