Tyres and Stopping
Tyres are probably the amongst the most important elements of safety on the roads as they are all that connects the car to the tarmac. Good tyre maintenance is essential in keeping us safe.
The law states that each tyre (included the spare) is in good repair and has no cuts or bulges visible to the eye and has a tread depth of a minimum of 1.6mm found around the central 3/4 of the breadth of the tyre and around the whole circumference. It is important each young driver has an understanding of these rules and indeed this could be a question found in the driving test itself. If you ask a tyre fitter they will often say that tread less than 3mm is considered as barely safe as anything less than this seriously increases the stopping distance of your car.
Regular checks of all the tyres is essential to save lives and money. For example a poorly inflated tyre or car with poor wheel tracking will shorten the life of the tyre and increase the danger if having an accident or blow out.
If tyres are damaged or under their legal requirements they should be replaced in pairs with 2 brand new tyres the same and tyre pressures should be equalised to the level what is set in the manufacturer guide for the vehicle. Partly worn tyres or Remoulds should be avoided as often these tyres cannot be guaranteed to be road worthy. Why take the risk…
Stopping distances – normal road conditions
The tread depth of the tyres actually vastly increases the stopping distance of the car. For example a car travelling at 50mph with a tread depth of 8mm (a new tyre) has a stopping distance of 14m shorter than the stopping distance with tyres with just the legal minimum of 1.6mm
Poor weather conditions
In wet driving conditions stopping distances double and in icy conditions they increase up to 10 times that of dry conditions. That said, when travelling at 70mph and braking it takes a car around 96m to come to a complete stop, so in icy conditions this increases to nearly 1km. Don’t gamble with poorly maintained or illegal tyres as this could be gambling with your life and the lives of other road users.
How to gauge stopping distances?
It is nearly impossible to picture a gap of 96m whilst travelling at 70mph and observing your surroundings to keep safe. It’s very annoying (and dangerous) when a car follows you closely but this is often due to the fact that drivers don’t know how to set a safe gap.
You should pick a fixed landmark ie a bridge or road sign and when the vehicle ahead passes this reference point you need to count to 2 seconds. Easiest way to do this is to say the following phrase out loud: “only a fool breaks the two second rule”. If you have passed the fixed reference point before finishing the phrase then you are too close and you safely need to back off.
Often this gap you are producing will appear very big as drivers around you might not be adhering to the gap and it will be tempting to decrease in. Don’t do it