UK-compliant headlights

25 April, 2025 Trying not to piss English drivers off.

• The headlight what?
• Stickerbombing the car
• Do they work though?

I drove to London on my Renault Zoe for research reasons and I initially wanted to write a post about the channel crossing as well the intricacies of driving on another side of the road. Thing is, the ferry was an extremely straightforward experience and while the driving itself did involve some readjustment and minor panic attacks, after a few hours it was barely noticeable. So what little curiousity left for me to write is a part of the trip preparation that some many not be aware of: the need to change the beam shape of the headlights and how it’s done.

Fig1. – Brave yellow Zoe near the coziest bar of the UK.

The headlight what?

Cars most commonly have two modes of the headlights: main beam and a dipped down one. As the name implies, the dipped down beam is tilted towards the ground not to blind the traffic. However the dip diminishes mid-way so that the shoulder remains well lit as it’s where animals and pedestrians may appear from. Some cars allegedly do not do this, presumably for cost saving reasons to keep the headlights the same across markets, but most do.

Fig2. – Criminally simplified main and dipped down beam shapes for a right hand drive car.

This presents a problem for international traffic. Continental Europe drives on the right, while the UK notably drives on the wrong left. The side reversal means that the additional roadside illumination goes right into the oncoming drivers’ eyes instead. The lights thus need to be adapted accordingly. Failure to comply theoretically can result in being pulled over, insurance denials in case of an accident and overall bad karma.

Certain modern cars have sophisticated headlight systems which allow them to change the beam shape from right to left hand driving right from the settings menu. My aging Renault Zoe doesn’t do that, even thought the beam switch is also done with a curtain. Stock Zoes have a famously pathetic headlights so the extra light is probaly not that much of a noticeable issue. But after my 2022 exploits I installed some madly bright aftermarket LEDs because I really didn’t feel like driving over some shrapnel leftovers. Even thought I tuned them very thorougly not to be that dazzling asshole, I only did so from my home driving side. How do I prevent British curses thrown at me?

Stickerbombing the car

Apparently the common answer to this problem is the sticker you put on the headlight to cover some part of the beam. I’m not entirely sure if there is only one company supplying those or not, but they are cheap enough compared to the rest of motoring expenses not to really put much thought into price comparisons. They come in two flavours: ones for left hand cars driving in right hand conditions and vice versa, with the Continental ones being targeted for French drivers and thus the instruction was entirely in French. But it’s very obvious and illustrative so even if I didn’t speak the language I wouldn’t have had much hassle.

Fig3. – The Eurolites package, the included reference and an applied sticker.

Do they work though?

¯\_(ツ)_/¯

Empirically speaking, I nobody flashed at me so at least I was no more annoying than the locals were. The police seemed not to be too bothered too. But that’s not good enough of a metric for me is it? So I decided to to some science and compare the beam with and without them.

Fig4. – The dipped down beam with the stickers (left) and without them (right).

Clearly some effect is there. On the left side, much of the extra light is gone aside from a very small protrusion. The right side did not fare too well at all. I took the pictures a couple of weeks after having applied the sticker and the right one looked noticeably withered away. This might have caused the sticker to malfunction. Or I could have wrongly applied it. Can’t really say for sure sadly. But in such state there isn’t much point to it since it’s exactly the right side that needs to be corrected the most. That said, Zoe’s dipped down beam shape doesn’t seem too bad as it is, so the whole thing might as well have been a placebo.

Fig5. – The part of the beam removed by the sticker and the visible wear on the right sticker.

So should you get them to drive in the UK if the car doesn’t support automatic switching? I think so. At a bare minimum they visibly attest that you do care about road safety which may keep you out of insurance trouble. But they seem to have a relatively short life, prepare to have a bunch of them for longer stays.