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Rear daytime running lights - davecooper

Not sure whether this has been discussed before but why are rear daytime running not required by law? How many newish cars do you see without any rear lights on in attrocious driving conditions. Seems like a no brainer to me but there is obviously a reason.

Edited by davecooper on 10/07/2023 at 22:53

Rear daytime running lights - Adampr

Not sure whether this has been discussed before but why are rear daytime running not required by law? How many newish cars do you see without any rear lights on in attrocious driving conditions. Seems like a no brainer to me but there is obviously a reason.

Well, because the front ones aren't either. They're just a slightly peculiar fashion.

Having proper lights on when necessary is required by law.

Rear daytime running lights - catsdad

I think your wires may be crossed here Adam. Perhaps you are thinking of the various ancillary lights some people add? Front DLRs are not a fashion item. They were required for new models from a date in 2011. Old models could still be produced without them

They became part of the MOT for cars registered after 1 March 2018. It’s a major fail if more than half the “bulbs” don’t work.

Rear daytime running lights - Adampr

I think your wires may be crossed here Adam. Perhaps you are thinking of the various ancillary lights some people add? Front DLRs are not a fashion item. They were required for new models from a date in 2011. Old models could still be produced without them

They became part of the MOT for cars registered after 1 March 2018. It’s a major fail if more than half the “bulbs” don’t work.

You're very kind, but I think I'm probably just wrong. I'm sticking to my guns, though, that they're not supposed to be a substitute for proper lights in bad weather.

Rear daytime running lights - paul 1963

Thing is most modern cars have automatic lights now, in poor weather all the lights come on.

Rear daytime running lights - Robert J.

I think they come on in response to light levels, not weather conditions.

Rear daytime running lights - paul 1963

I think they come on in response to light levels, not weather conditions.

Goes hand in hand surely? I know the lights illuminate on both my car and van in the rain..

Rear daytime running lights - Lee Power

Thing is most modern cars have automatic lights now, in poor weather all the lights come on.

Unless its foggy, not seen any automotive manufacturer manage to get an automatic light system to detect fog yet.

As for rear DRL, I know newer PSA stuff ( which likely also included Stellantis products on PSA platforms ) will illuminate the rear tail lights with the front DRL, its a setting in the BSI configuration set up which some owners with older vehicles tweak to activate the function.

Rear daytime running lights - elekie&a/c doctor
I think the original Volvo system from the 70s is a better idea . All the position lights work front and rear when ignition turned on , plus brighter front Drls. Once the headlights are switched on, the front Drls are extinguished,
Rear daytime running lights - Lee Power
I think the original Volvo system from the 70s is a better idea . All the position lights work front and rear when ignition turned on , plus brighter front Drls. Once the headlights are switched on, the front Drls are extinguished,

You can do something a bit similar ( no DRL's ) with some of the early PSA multiplexed stuff - normally there's a setting in the BSI configuration set up to illuminate the dipped headlights / taillights with the engine running, its set to OFF for the UK.

Rear daytime running lights - mcb100
‘ As for rear DRL, I know newer PSA stuff ( which likely also included Stellantis products on PSA platforms ) will illuminate the rear tail lights with the front DRL, its a setting in the BSI configuration set up which some owners with older vehicles tweak to activate the function.’

You can tell a PSA/Stellantis car from the rear on DRL’s as opposed to headlights as the number plate lights won’t be on.

Agreed as above, the number of cars I see on the motorway in the dark just on front DRL’s is notable. And they will inevitably have auto lights.

I’d make two changes to legislation -
If the cars speed is at 50mph or greater, and the wipers are running, I’d have the headlights & tail lights automatically switch on.
I’d stop the dashboard illuminating when DRL’s are on. If a driver can’t read the instruments then it’s more likely to trigger a realisation that the rest of the car isn’t illuminated.
Rear daytime running lights - sammy1

Are yes DRLs for the semi blind motorists who cannot see other vehicles on the road. Seriously some DRLs have got so bright now that they are a pain. As to rear ones well drivers have the option of their rear fog light but few use them and the odd driver never switches theirs off again

Rear daytime running lights - FP

"Are yes DRLs for the semi blind motorists who cannot see other vehicles on the road."

Are you seriously against DRL as a safety feature? Or is this another of your "I'm only joking" comments?

By the way, rear fog lights may legally only be used in reduced visibility and many function only when the headlights are switched on. Therefore they are not a substitute for ordinary rear lights.

Rear daytime running lights - sammy1

"Are yes DRLs for the semi blind motorists who cannot see other vehicles on the road."

Are you seriously against DRL as a safety feature? Or is this another of your "I'm only joking" comments?

By the way, rear fog lights may legally only be used in reduced visibility and many function only when the headlights are switched on. Therefore they are not a substitute for ordinary rear lights.

No I am not against DRLs I just do not see them as that important to me anyway. I am perfectly aware of the laws relating to front and rear fogs. However many display front fogs in daylight as they probably think they look cool. Same really as your front DRLs they have largely become a design feature with too bright LEDs and the rest. You should not be driving if you cannot pick out cars without DRLs and there are plenty of them

Rear daytime running lights - Manatee

>>You should not be driving if you cannot pick out cars without DRLs and there are plenty of them

That's not really the point. They are less likely to be overlooked with DRLs on. It is possible to look, without seeing, as I'm sure you know. Ask the people who have knocked off cyclists and motorcyclists at roundabouts.


www.thedrivingecademy.com/blog/fighterpilot

Rear daytime running lights - Andrew-T

They are less likely to be overlooked with DRLs on. It is possible to look, without seeing, as I'm sure you know.

I would object less to DRLs if the parsimonious designers would make them dimmer after dusk. Clearly they must be fairly bright in daytime, but not blinding otherwise.

Rear daytime running lights - mcb100
They do dim as the lights are switched on, either manually or automatically.

My Megane uses the same units as both DRL and sidelight, obviously brighter during the day.
Rear daytime running lights - Manatee

I would object less to DRLs if the parsimonious designers would make them dimmer after dusk. Clearly they must be fairly bright in daytime, but not blinding otherwise.

The ones that stay on with the headlamps (the 'decorative' ones?) normally dim when the proper lights are on. Those on the MX-5 just go off and stay off, as they should IMO.

I suppose you mean that where proper lights are not in use, they should dim according to light levels. I agree. But they seem to depend on driver having the wit to use proper lights when it's dark.

Then there's fog... lots of cars with front DRLs on and nothing at the back.

If we going to have nannies, they should at least work when really needed.

Rear daytime running lights - Andrew-T
I’d make two changes to legislation - If the cars speed is at 50mph or greater, and the wipers are running, I’d have the headlights & tail lights automatically switch on. .

Automation is all well and good, up to a point. If your suggestion were implemented, would the lights continue switching on/off as the car's speed went above or below 50 (or whatever threshold seemed appropriate) ?

Rear daytime running lights - mcb100
‘ Automation is all well and good, up to a point. If your suggestion were implemented, would the lights continue switching on/off as the car's speed went above or below 50 (or whatever threshold seemed appropriate) ?’

Yes.
Rear daytime running lights - Andrew-T
‘ Automation is all well and good, up to a point. If your suggestion were implemented, would the lights continue switching on/off as the car's speed went above or below 50 (or whatever threshold seemed appropriate) ?’

Yes.

Not an ideally clever device then ?

Rear daytime running lights - mcb100
I’m not sure how clever it needs to be.
Increased speed, added to lessened visibility, leads to an increased need for illumination.
Reduce the speed and less need for lights.
As an alternative, automatically on at 50mph, going off as speeds reduced to 30mph.
Any cleverer?
Rear daytime running lights - Adampr
I’m not sure how clever it needs to be. Increased speed, added to lessened visibility, leads to an increased need for illumination. Reduce the speed and less need for lights. As an alternative, automatically on at 50mph, going off as speeds reduced to 30mph. Any cleverer?

My lights come on with the windscreen wipers regardless of speed. Seems reasonable to me

Rear daytime running lights - Andrew-T
I’m not sure how clever it needs to be. Increased speed, added to lessened visibility, leads to an increased need for illumination. Reduce the speed and less need for lights. As an alternative, automatically on at 50mph, going off as speeds reduced to 30mph. Any cleverer?

That would be better. I was just imagining following a car cruising at ~50 with the lights going on or off by turns.

Rear daytime running lights - Manatee

The Mk4 MX-5 has rear DRLs.

Actually they look as if they are the position lights, but they come on with the front DRLs.

The other possibly odd thing about the MX-5 DRLs is that they come on when the car is moving, and go off when it stops.

I followed a Nissan Leaf (I think) for at least 10 miles on Sunday in darkening crepuscular light, no sign of any rear lights. When I overtook, I found it had dazzling front DRLs on - of course, they are bright because they are designed to be seen in daylight, nor are they 'aimed' in any way. I'm pretty sure the driver was using them to see by!

Edited by Manatee on 11/07/2023 at 12:07

Rear daytime running lights - davecooper

If there was a good reason for bringing in legislation for front DRL's then that same reason would seem to be applicable to rear lights as well. I agree that most newer cars have auto headlights but I am still amazed at how many newer cars still have no rear lights on in bad weather.

Another thing I always found fascinating is that you can have an HGV with the front lit up like Blackpool illuminations with more colours than your average Christmas tree yet at the back there are piddly little side lights smaller than many cars.

Rear daytime running lights - misar

If there was a good reason for bringing in legislation for front DRL's then that same reason would seem to be applicable to rear lights as well. I agree that most newer cars have auto headlights but I am still amazed at how many newer cars still have no rear lights on in bad weather.

A major reason for legislating front DRLs is to make oncoming vehicles more visible to pedestrians and cyclists. Rear DRLs are irrelevant for that purpose.

Rear daytime running lights - Sofa Spud

On my car the dipped headlights and the tail lights come on whenever the engine is running.

This seems much more sensible than having separate daytime running lights and it should become a legal requirement.

Rear daytime running lights - sammy1

If you want to dip your headlights try driving into a stream! DRLs these days are all about looks and style not function and not required on the rear. In fact vehicle lights, indicators etc have gone just stupid. My favourite gripe is the tiny rear indicators that you have a job to see and driving behind new Audis is like being at the fair with strips of light across the back.

Rear daytime running lights - corax

My favourite gripe is the tiny rear indicators that you have a job to see and driving behind new Audis is like being at the fair with strips of light across the back.

Next idea around the office table will be rear lights able to produce symbols like a moving hand with an index finger pointing sideways when the indicator is used.

Rear daytime running lights - mickyh7

Reading this post and one of it's it's contributors.

Twisting on 21 springs to mind!

Rear daytime running lights - sammy1

My favourite gripe is the tiny rear indicators that you have a job to see and driving behind new Audis is like being at the fair with strips of light across the back.

Next idea around the office table will be rear lights able to produce symbols like a moving hand with an index finger pointing sideways when the indicator is used.

More like the middle finger from the usual culprits who do not indicate!

Rear daytime running lights - davecooper

Never been a fan of the Audi dynamic indicators but that was an Audi gimmic so I had no real issue with them (apart from possibly solving a problem that didn't exist). However, now everyone is copying them, even lorries. Why!

Back in the 90's I spent time US and there were cars fitted with dynamic brake lights where more lights lit up across the back depending on how hard the brakes were applied. They may still exist for all I know. This seems like a more useful feature than dynamic indicators.

Rear daytime running lights - Smileyman

This is real problem at twilight when the rear lights are not illuminated and vehicles become semi - visible. My 2017 car does include rear lights illuminated when the engine is running, and the dashboard goes dark if the ambient light is low ... thus encouraging me switch on the headlights (no automatic lights) .. EU or no EU some things should be mandatory for all new vehicles.

Rear daytime running lights - gordonbennet

More dumbing down, this time of an already severely deskilled driving population, where lights have to be automatically on because too many people are no longer in charge of their own vehicles...just another example of one size fits all..because some clot who shouldn't drive can't drive everyone else is assumed to be equally useless.

DRLs are doing what hivis clothing has done, instead of being noticeable there are now so many silly fairy lights about that they blend into the background.

Amuses me when i see LED lights on a car advert, all it makes me do is want to avoid the thing because sooner or later the LED will fail and instead of a 50p bulb to replace it's typically from £300 upwards each unit.

Cars don't need rear DRL's, they don't need front ones either, they need a competent switched on driver, the type who can see what's going on all around and who for example can control a vehicle on a hill without the car assisting via yet more electronic faff.

Edited by gordonbennet on 15/07/2023 at 05:53

Rear daytime running lights - Ex Alfa mail

Gordon, if there were an ability to uptick your comment I would be doing so with gusto!

Rear daytime running lights - sammy1

Gordon, if there were an ability to uptick your comment I would be doing so with gusto!

Agree, but with so many cars being painted in battleship grey may be we should stick with the DRLs as they appear out of the gloom.

Rear daytime running lights - Andrew-T

Gordon, if there were an ability to uptick your comment I would be doing so with gusto!

Agree, but with so many cars being painted in battleship grey may be we should stick with the DRLs as they appear out of the gloom.

Round here the preferred colour seems to be Black ! Equally invisible ?

Rear daytime running lights - FP

GB, I take your point and it may well be wholly or at least partly true, but if a feature like DRLs actually helps with road safety I'm all for it.

You could go back through the history of automotive development and point to lots of things we now entrust to the machine and not our skills. For example, you could have argued many years ago that a competent driver should master changing gear on a non-synchromesh box.

You need to remember that, however high the standards you and I set for ourselves when it comes to competent driving, there are other incompetent and careless fools out there who cannot or will not reach that standard.

Rear daytime running lights - misar

More dumbing down, this time of an already severely deskilled driving population, where lights have to be automatically on because too many people are no longer in charge of their own vehicles...just another example of one size fits all.. because some clot who shouldn't drive can't drive everyone else is assumed to be equally useless.

The logical conclusion of your argument is that all motoring legislation is unnecessary dumbing down.

Why have speed limits - skilled drivers know how to set their speed.

Why have lighting up times - skilled drivers know when to turn on their lights.

Why have the MoT - - skilled drivers maintain their cars correctly.

And so on ...

Rear daytime running lights - gordonbennet

The logical conclusion of your argument is that all motoring legislation is unnecessary dumbing down.

Why have speed limits - skilled drivers know how to set their speed.

Why have lighting up times - skilled drivers know when to turn on their lights.

Why have the MoT - - skilled drivers maintain their cars correctly.

And so on ...

I suppose i'm interested in this dumbing down because its been happening for a numbers of years in my own industry, in which i've been driving trucks for well over 40 years.

Much as in cars the idea is to eventually remove the driver from the vehicle except for an alleged supervisory role, well all i can say to that is good luck everyone when what will probably be a 50+ tonner has an error 404 crop up and goes off on its own.

Oh its alright they say because there'll always be a qualified driver in attendance, well again i say good luck with that, when our no longer hands on driver who hasn't been paying attention to what's been happening all around anyway has to make a split second decision to save the now error stricken vehicle from causing mayhem, said driver won't just be caught in surprise he/she will by then be so decondtioned from actual vehicle handling and control as to be virtually useless.

By all means pick holes, that's what a discussion is for, but one should always be careful of what they wish for and the laws of unintended consequences, not all progress turns out to be for the best.

Rear daytime running lights - misar

By all means pick holes, that's what a discussion is for, but one should always be careful of what they wish for and the laws of unintended consequences, not all progress turns out to be for the best.

True but equally not all progress turns out to be for the worst. Only history can judge the value of most innovations.

Without progress you might have been driving a horse and cart, not a truck, for well over forty years. Had you been around at the start of trucking you would no doubt have decried the innovation as dumbing down from the ability required to care for and handle a horse. Perhaps you still do.

Rear daytime running lights - Manatee

It's hard to argue DRL's are not a good idea, I've already given a link to the old article that makes the case very well. Contrast makes things easier to see.

www.thedrivingecademy.com/blog/fighterpilot

As to rear lights, it's always been very common to see cars in fog, for example, not carrying rear lights. Now, with DRL's there is a tendency for people deliberately or inadvertently to delay lighting up because they already have some relatively very bright (in twilight) DRL's on the front.

Automatically having rear lights on with DRL's addresses both of these problems and I fail to see why that shouldn't also be legislated.

Auto lights are a different question. They are not obligatory AFAIK and they are unnecessary. They also create a problem in that it seems more common now for people not to put headlamps on in poor visibility, where overall light levels mean that they don't come on automatically - an example of a nanny feature making drivers dumber.

But, pragmatically, many are pretty dumb anyway. We shouldn't leave them to figure it out, because they won't. So DRL's deal with the world as it is, not as it should be.

You can have similar debates about

blind spot monitoring,

cross traffic alerts,

lane-keeping,

adaptive cruise control, and

autonomous emergency braking.

They can all become a substitute for paying attention. I haven't actually heard anybody say yet, after a crash, "it wasn't my fault, I never saw the blind spot warning", but it's only a matter of time.

Rear daytime running lights - Adampr

I really don't think anyone believes that DRLs are adequate at night. They have automatic lights and assume they will switch on at the relevant time.

Certainly in my Skoda, there is no way to tell whether the lights are on and off short of looking around the steering wheel towards your right knee to see if the switch is illuminated or not. I am reasonably diligent about doing so, but many people will assume that automatic means automatic.

I tend to agree that the best solution is just for the lights to come on when the engine is started.

Rear daytime running lights - Andrew-T

<< It's hard to argue DRL's are not a good idea, I've already given a link to the old article that makes the case very well. Contrast makes things easier to see. >>

Like many earlier clearly 'good ideas' they are fine to begin with. The contrast you mention has to be ratcheted up as the good idea spreads. Hence we get increasingly bright headlamps in a leapfrogging war, causing obvious problems for many.

In Victorian times it was not too difficult for railway drivers travelling at 60mph to pick out signals lit only by paraffin lamps, because there weren't too many other lights around. Try to imagine doing that these days ?

Rear daytime running lights - gordonbennet

Go back even a couple of decades and everyone in London drove around at night on side lights, and i mean 5w filament bulbs.

As Andrew alludes to this preserved night vision to a decent extent and pedestrians and cyclists etc didn't disappear as they now do in the increasing light wars where night vision is destroyed.

S'ok i know there's no going back.

Rear daytime running lights - Manatee

I don't think the suggestion that "DRL's become ineffective when all cars have them" really washes. They will certainly be less remarkable/noticeable, but they remain visible.

Brightness is legislated. But of course the permitted brightness would be dazzling at night. They must turn off when the headlamps are on but this seems to be interpreted as 'dimmed' by some manufacturers who choose to display their 'brand' pretty patterns.

I don't think there is a perfect answer to this until auto-lights all detect visibility as well as total light.

Rear daytime running lights - John F

.... sooner or later the LED will fail

Not yet...

.....and instead of a 50p bulb to replace it's typically from £300 upwards each unit.

....and not so. My 2005 Audi was one of the first cars to have LED DLRs. It also has the facility to switch them on and off with ease via the 'multi media interface' controls, so they remain off when the lighting is good on ordinary roads. But I always switch them on for dual carriageways. So far, none have failed. if they do, a complete set is apparently available for less than £45, which admittedly is pricey for what they do.

www.autodoc.co.uk/tech/14354268

Rear daytime running lights - HGV ~ P Valentine

Adamor is right.

Lights are required at all times visability is reduced,

Heavy rain, fog, and one most people do not use in any tunnel. The latter because it makes it easier even in bright sunlight for others to see you in their mirror, esp when exiting the tunnel. Also, so you can see the speedo if you do not have a digital display. A lot of vans, and some cars have the speedo buried so no natural light can get to it, so in this case some lights are required at all times.

The reason why people do not is simple. The i**** factor, like all of us I have seen people driving in fog with no lights at all, and in heavy rain where the spray from standing water hides the back of their vehicle.

Overview (rule 226), Hide

Rule 226

You MUST use headlights when visibility is seriously reduced, generally when you cannot see for more than 100 metres (328 feet). You may also use front or rear fog lights but you MUST switch them off when visibility improves (see Rule 236).

Edited by HGV ~ P Valentine on 31/07/2023 at 09:44