What's the point of front fog lights?

Advocado

Driving in fog last night, for a few hundred metres it got genuinely very thick.

So for the first time in my life, I turned on my front fog lights and they did... absolutely nothing.  Are they supposed to light up the road?  Because they don't.

MX5huggy

They are more for others to see you, in the days of pathetic dipped beam tungsten bulbs they were a great help. 

daveyjp

In all my driving years I have had need to use them maybe 2-3 times when it was a real pea souper.

In very heavy fog (i.e less than 50m visibility) a headlight beam bounces off the fog and is very disorientating.  You therefore turn off headlights and use sidelights and front fog lights.  That way you illuminate the road just in front of the car, but other drivers can see you.

motorguy

daveyjp said:

In all my driving years I have had need to use them maybe 2-3 times when it was a real pea souper.

In very heavy fog (i.e less than 50m visibility) a headlight beam bounces off the fog and is very disorientating.  You therefore turn off headlights and use sidelights and front fog lights.  That way you illuminate the road just in front of the car, but other drivers can see you.

Exactly it.  Very rare they're of any actual use but there are still times.

Merlin139

For people to have them on all the time so they can be seen by the person whom they are catching up very fast and want you to move out of the way!

Then you get the Rear Fog Light user! Turn them on and forget about them even when they can see the light on the dashboard!

I think Fog Lights should be used when visibility drops below 100m from what I can remember. Most times I see either front of rear visibility is between 1 to 3 miles!

Typhoon2000

Front fog lights really illuminate the road/curbs/ verge and lane marking right infront of you, when you the visibility is really poor that you can’t see the road right in front. Head lights and dipped beams illuminate the road further ahead. So fog lights are not going to aid you in seeing the road up ahead in fog, but will help keep you in your lane and follow the road especially on unlit roads and lanes. Naturally you would be driving suitably slowly if you have need to switch on your front fog lights.

peter_the_piper

Imagine you are driving in thick fog and there's a car trying to pull out of a side road on your side. Without the fog lights you'd possibly crash into him cos he didn't see you.

greyteam1959

I presume the OP has checked that the fig lights actually work ??
That they illuminate when switched on.

daivid

daveyjp said:

In all my driving years I have had need to use them maybe 2-3 times when it was a real pea souper.

In very heavy fog (i.e less than 50m visibility) a headlight beam bounces off the fog and is very disorientating.  You therefore turn off headlights and use sidelights and front fog lights.  That way you illuminate the road just in front of the car, but other drivers can see you.

That would be illegal, highway code (and RVLR laws) state you must use headlights when visibility is seriously reduced. Besides I've never been bothered by reflection of dipped headlights, and as others have said using front fogs helps show up the road and markings and importantly helps others see you.

Sea_Shell

I've often wondered why front fogs aren't also wired up to full beam?

So when on full beam (not in fog, obvs) you get ALL the forward facing lights available to you.

You wouldn't dazzle anyone, as you'd knock off full beam as usual for any oncoming traffic.

Rover_Driver

daivid said:

daveyjp said:

In very heavy fog (i.e less than 50m visibility) a headlight beam bounces off the fog and is very disorientating.  You therefore turn off headlights and use sidelights and front fog lights.  

That would be illegal, highway code (and RVLR laws) state you must use headlights when visibility is seriously reduced. 

There is an exemption for the use of compliant foglights in place of headlights in seriously reduced visibility - Road Vehicles Lighting Regulations 1989, Reg.25,(2),(b),(ii).