Driving in Fog

Foggy weather makes driving conditions very difficult – you need to take some basic precautions to ensure your safety if you have to drive when the weather is foggy.
Avoid using full beam headlights at night because your own light will reflect back off the fog and your vision will be reduced. Full beam headlights can also make it more difficult for others to see properly.
At junctions (particularly when turning right wind down the window to help you hear if other vehicles are approaching – consider using your horn to warn any approaching vehicles of your presence.
If you are stopped waiting to turn at a junction keep your foot on the brake pedal – the extra lights will help other drivers to see you earlier.

Daytime Fog
It is a legal requirement to turn on your lights when visibility is reduced to 100 metres or less. Use your headlights and fog lamps to enable others to see you.

Rear Fog lights
High intensity rear fog lamps are designed for thick fog, typically 80 metres or less visibility. Using rear fog lights when visibility is greater than this can mask your brake lights and dazzle other drivers, thus increasing the risk of a rear-end collision rather than reducing it.
Think of rear fog lamps as signals. Put them of as soon as they have done their job. For example, if you are in a slow moving queue of traffic in fog, the driver 5 metres behind doesn't need your fog lights!
You will see many drivers switching on their rear fog lights when the weather is a little misty – don't follow their example – only use the fog lamps when driving conditions make it necessary.

Front fog lights
Front fog lights reduce the amount of reflected light. At night you will get most benefit from front fog lamps, especially on roads with street lighting, if you switch off your headlamps. Other drivers will still be able to see you and you will see more clearly.

Maintaining your distance
Many drivers forget all about maintaining a safe separation distance in foggy conditions – you will see other drivers following leading vehicles closely in an effort to benefit from the others drivers' rear lights.
Because of the reduced visibility there is an increased risk of the vehicle in front of you stopping quickly – if the driver is using rear fog lights his brake lights may be masked and you would have less warning than usual when he applies the brakes.
Because fog is composed of water droplets suspended in the air – the roads are always going to be wet – your following distance should be increased (allow at least 4 seconds separation) to allow for the prevailing conditions.

Driving in fog should be avoided if possible – if you have no alternative follow the advice given here to keep yourself safe.

How the brakes work

• The foot brake operates the brakes on all four wheels. Typically, the braking system on a modern front wheel drive car comprises two hydraulic systems. Each is connected to a front and a rear wheel. This ensures that should there be a leak of hydraulic fluid from either system, at least half the braking force will still be available.
• Note any variations in the braking efficiency. If the brakes feel spongy or the vehicle pulls to one side when braking, get them checked by a qualified mechanic.
• Excessive use of the foot brake, particularly when travelling down a long steep downhill gradient, will normally cause the brakes to overheat and they are liable to become less effective. This is known a Brake Fade which is more likely to happen on cars fitted with drum brakes, but it can still apply to those fitted with disc brakes as well. To assist with the control of the car and avoid brake fade, it is advisable to make use of an appropriate lower gear in accordance with the steepness of gradient. The handbrake or parking brake is used to hold the car still after it has stopped. It operates on two wheels only (usually the back) and, unlike the other brakes, it is mechanically operated.
  
  

Tyre Maintenance

• Examine tyres every two weeks for signs of damage, uneven wear, splits or cracks.
• Keep track of tyre tread depth by purchasing an easy-to-use tread depth gauge. The legal requirement is 1.6mm, but many manufacturers recommend changing at 2mm or even 3mm.
• Check tyres are inflated to the correct pressure every week using a reliable gauge. Do this when the tyres are cold.
• Tyres will wear at different speeds especially between front and back. Don't presume all tyres will be in the same condition.
• Ask a garage to check the vehicle's tracking every six months, or after any collision or heavy kerb impact. Incorrect tracking leads to uneven and accelerated tyre wear.
• Aggressive driving styles can take thousand of miles from the life expectancy of tyres. Harsh acceleration and braking will reduce the tread significantly.
• When changing tyres, never risk buying part worn or second-hand tyres, a brand new tyre or retread is always a safer investment.
• Caution! Remember tyre age. Never use a tyre over Six Years old, regardless of whether it has been used or not.
• At least every week check the tyre pressure (including spare). Incorrect tyre pressure may adversely affect tyre life and vehicle handling. Tyre pressure should be checked when tyres are Cold after the vehicle has been parked for three or more hours, or driven less than 1 mile. COLD tyre pressures are shown on garage forecourt. Different vehicles have different tyre pressures so check the charts.
• Insufficient pressure can lead to overheating of the tyre and subsequently internal damage. At high speeds, this could result in tread separation and even bursting of the tyre.
• Tyres should also be inspected for wear, cracking, bulging, or objects caught in the tread. If excessive wear, cracks, bulging, or deep cuts are found, the tyre should be replaced.
• Most new tyres have a built-in tread wear indicator (See diagram). When wear indicator is visible, the tyre should be replaced.
• Cars must have a tread depth of at least 1.6mm across the central three-quarters of the breath of the tread and around the entire circumference.
• Do not use a deformed wheel even if it has been repaired. Such wheels could have structural damage and could fail without warning.
• Unbalanced wheels may affect vehicle handling and tyre life. Even with regular use, wheels can get out of balance. Therefore, they should be balanced as required.

Motorists often fail to check the condition of their tyres, which could have fatal consequences, Although tyres are critical for the safety of all road users, many motorists are in breach of, and, oblivious to, the legal 1.6mm tread depth requirement, and may have tyres classified as severely damaged. With a maximum fine of £2,500 per tyre with discretionary disqualification including three penalty points, motorists could be in for a nasty shock, if caught driving with illegal tyres.

How to change a tyre.

Next time you have a damaged or flat tyre, don't look for a mechanic. Just follow these simple steps and change it yourself.

When on a motorway – Never change a flat tyre on the hard shoulder. Breakdown patrols are trained to do roadside repairs safely, while their flashing lights are much more noticeable than your car's hazard lights.

Choose a safe place to stop away from the main carrigeway and ensure your passengers get out of the car and wait in a safe area away from other traffic.

• Switch on the hazard warning lights to alert other road users. Apply the handbrake and engage 1st gear 9 select 'P' for an automatic transmission)
• Ensure the jack is positioned on firm, level ground. Do not position the jack on metal gratings or manhole covers.
• If jacking on a slope, place chocks (a house brick would do) at the front and rear of the wheel diagonally opposite the one to be removed.
• Before raising the car, remove the wheel trim and use the wheel nut spanner to slacken each of the wheel nuts anti-clockwise.
• Turn the jack clockwise to raise the car until the tyre is clear of the ground.
• Remove the wheel nuts and the wheel
• Fit the spare wheel and tighten the wheel nuts (domed side towards the wheel) until the wheel is firmly seated.
• Lower the car and remove the jack and the wheel chocks, then FULLY tighten the wheel nuts in diagonal sequence.

Refit the wheel trim.

Some more lighting checks.

• Lights are easier to check on a dull day or when daylight is fading.
• SIDELIGHTS
  Two white at the front; two red at the back. Should be bright and of equal intensity. Look closely at the rear lights to see if there is a dim glow from the brake lights, turn indicators or high-intensity fog lights — this may mean a poor earth to the car body on the nearest sidelight. If the front sidelights are small bulbs set in the headlight reflector these may be dim — these little bulbs tend to overheat and go black inside. Not a MOT fail point as such if they are both equally dim, but it's best to replace them.
• REAR FOG LIGHT(S)
  Switch on the high-intensity red rear light(s) — your headlights need to be on dipped beam. If fitted, fog lights must work, so must the interior 'tell-tale' light on the instrument panel.
• LENSES & REFLECTORS
  Headlamp reflectors must be bright and not obviously misted, tarnished or corroded. The headlamp lens should not have any hole or a crack that could let in water. All plastic lenses covering the other lights should be the correct colour and not excessively faded.