1 hour ago, silver1011 said:

If fog lights were used correctly (front and rear) then you could have four or more of them for all I care.

 

In real thick fog, the more rear visibility the better, whether the fog lights obscure the brake lights doesn't matter, as you'll be a safe distance from the car in front and speeds will be very low, allowing you to react appropriately with or without brake lights.

 

Fog lights should be used when visibility reduces to below 100 metres (328 feet). This isn't very far at all.

 

The mere whiff of a little morning mist around here and everyone whacks their fog lights on, and then leave them on for the rest of the day.

 

I live in the vale of York, so fog is something I deal with all year round. I reckon I experience a sufficient reduction in visibility to justify the use of rear fog lights once or twice a year, tops.

100% agree, far too many people turn on their fog lights when there clearly isn't less than 100 metres visibility.

 

As an example, on Monday on the M5 near Taunton there were several cars with rear fog lights on - there was some spray but visibility was at least a mile.

I'd rather err on the safe side and turn mine on when visibility gets poor.

100m isn't far at motorway speeds.

25 minutes ago, gregoir said:

I'd rather err on the safe side and turn mine on when visibility gets poor.

100m isn't far at motorway speeds.

 

100m is considered the stopping distance for travelling at 70mph (actually around 75mph)

If you can safely do these speeds, then you're not down to 100m of visibility due to fog.

37 minutes ago, gregoir said:

I'd rather err on the safe side and turn mine on when visibility gets poor.

100m isn't far at motorway speeds.

 

Doing motorway speeds with 100 metres of visibility is why this happens...

 

 

If visibility is reduced enough to justify fog lights then we should be talking of speeds around 30mph.