Now we have covered the basics of getting you to look outside of your vehicle to gather more informa­tion, we should briefly take into consideration the forces acting on your vehicle should you need to make a change of speed or direction in order to avoid any  problems.

Weight is a critical factor in vehicles. If your vehicle is full of equipment for your work, try to spread the weight and secure the heavy items securely. There is nothing worse than when you brake hard and the contents of your vehicle continue moving forward. I have already mentioned the benefits of using a van and this is yet another one. Having to carry equipment around is a nuisance, but in a van it can be ac­commodated without compromising the safety of the vehicle too  much.

The other problem with weight is how it affects handling and other characteristics of your vehicle. Hav­ing the correct shock-absorbers, tyres and importantly tyre-pressures, will all help to offset this problem. Too much equipment in the boot of your car may not be noticeable in normal driving, but as soon as you brake hard or swerve to avoid a hazard , you will find the vehicle wanting to "swap-ends" with catas­trophic results. If you must carry heavy equipment, try to carry some inside the passenger cell and therefore between the axles, thereby distributing the weight more evenly.

After you have taken care of the weight problem, balance can be maintained more readily if you remem­ber to always brake and steer smoothly and precisely. Sudden or jerky movements are the most com­mon cause of control loss - especially those caused when braking on the approach to a bend. Most drivers fumble with their gear-levers while braking, often changing through the gears for no reason. This is an antiquated approach as engine braking is neither desirable or very necessary in modern driving.

Always concentrate on removing all excess speed first, then changing gear to the required gear for the bend or other hazard. Then as you accelerate through the hazard, both hands can return to the wheel to maintain control.

This may sound a little like stating the obvious, but again very few drivers actually do this as it is not a natural skill to learn. Most drivers are still  changing though the gears as they were taught many years  ago, although many go through the motions without releasing the clutch between gear-changes, which means they are in fact approaching the bend out of gear, with one hand on the wheel and with limited control if things go wrong. This is one area which has been amended in the driving test and now you    can be marked down for changing down gears for no reason. Control is gradually becoming more impor­tant in order to reduce the accident rate among younger drivers and this is seen as one way of achieving this easily and safely.

LGV

Large Goods Vehicle used to be known as Heavy Goods Vehicle or  HGV.

The available grip on modern roads is notoriously variable, with road surfaces breaking up all over the country and "patching" taking place to provide temporary repairs rather than complete new surfaces.  Grip depends on the "footprint" of your tyre on the road surface and the quality of the surface that it makes contact with. If, for example, the two nearside wheels of your vehicle are on good tarmac, but the two offside ones are on a worn patch caused by LGV's braking , any attempt t.o  brake will result in a  sharp veer to the left. This surprises many drivers and then panic sets in , causing more severe control  loss.

Aquaplaning

The effect caused by a build-up of water under the tyres of a moving vehicle.

Try to consider the size of each tyre's footprint, multiply it by four and remember that this is all that is keeping you on the road. In the wet it can be reduced by the surface water and tyre wear. A new tyre can expel twelve gallons of water per second, per tyre at 60mph. A worn tyre proportionally less of   course and a worn tyre on a saturated road hardly any. Hence the common effect called 'Aquaplaning' which can affect any vehicle travelling at  over 40mph. The best  description of aquaplaning that  I have ever heard is "surfing with a tonne of car strapped to your  butt".

Needless to say this was an American definition but certainly describes the feeling of helplessness that arises once the car begins to aquaplane. Once you feel control being lost, lift off the accelerator, but do nothing else until contact with the road is restored. You do not want to hit the road surface at speed with your wheels turned at 45 degrees and suddenly find yourself spinning out of control. This is the same as skidding on ice and better avoided than experienced for real.

From these examples, you can see the benefit of correct balance and weight distribution. What is less obvious is the difference between classes of vehicle. Many of you will be driving 4x4 vehicles, although not necessarily off-road vehicles in the true sense, but urban off-roaders designed as leisure vehicles. Unfortunately they have one drawback that is seldom mentioned when purchased. The higher than usual centre of gravity makes them considerably more unstable at speed or when turning sharply. Vans are similar, but less severe than 4x4 vehicles due to wider track and a lower floor.

This difference must be taken into account when practising the braking exercises and other routines mentioned in this manual. You are responsible for knowing the limitations of your own vehicle and we cannot accept responsibility for any difficulties that you may suffer through over­ zealous use of the techniques recommended in this manual. Remember that only you can control your vehicle's condition, the position of your tyres and the speed you are travelling at. If you leave the road, there is often no-one to blame but yourself!