Driving in fog can be difficult and dangerous, especially considering fog is most likely to occur early in the morning and later at night, during key commuting times.
To help navigate such conditions, the AA have shared some tips on how to drive in the fog and stay safe on the roads this winter. But first, how is fog formed?
What is fog?
Essentially, fog is a formation of clouds sitting at ground level. It occurs “when air saturated with water vapour is cooled suddenly,” according to the BBC’s Science Focus magazine.
Fog “causes a reduction in visibility to less than 1,000 metres,” says the Met Office. This distinction is important for differentiating fog from mist, which is a common mistake. The difference between the two comes down to visibility.
“If you can see more than 1,000 metres, it’s called mist, but if it is thicker and the visibility drops below 1,000 metres, it’s called fog,” the Met Office continues.
Foggy conditions are most common between October and March.
How to drive in the fog
Most drivers know to slow down and turn their fog lights on to help other drivers see them, but fog on the road also has a hazardous impact on driver’s speed perception, the Met Office warns.
“Much of how our brains judge speed is by the contrast in our surroundings, such as trees or buildings flashing past in our peripheral vision,” they explain.
“But in foggy conditions, contrast is greatly reduced, giving the impression you are driving slower than you actually are. Many drivers increase their speed as a result.”
To help drivers contend with thick fog, the AA has listed its top tips:
- Use dipped headlights to prevent glare
- Use wipers and de-misters to remove moisture
- Use fog lights
- Beware of other drivers not using headlights
- Only drive as fast as conditions allow
- Slow down to allow for a greater stopping distance
- Allow three seconds instead of two between you and the car in front
- Check your mirrors before you slow down
- Open your window to listen for traffic at junctions if you can’t see
- Use your speedometer to judge your speed
- Don’t rely on automatic lights – they might not come on in fog
- Don’t rely on daytime running lights alone – they only light the front
- Don’t tail another car’s rear lights – it can give a false sense of security and it’s dangerous
- Don’t speed up to get away from a vehicle that’s too close behind you
