"In every study that considered the question"

The parking lights vs low beam icon are quite standard, at least in the EU, and they tell you the difference when getting your licence.

Icons are still the same as they were 25 years ago AFAICT.

"Many cars have an AUTO option now, but would you trust it to choose the right thing? I didn’t, being unsure if it properly accounted for daylight rain driving."

While it doesn't negate the iconography discussion throughout the rest of the article, the AUTO option is the intended default, because it turns on low beams in every case where they're needed, including daylight rain driving, which is based on the use of windshield wipers. I'm always a bit baffled at the modern cars driving around without their lights on. The car does it for you these days.

The ability to select low beams vs daylight running lights (DRLs) is mostly for convenience for one-off odd circumstances where you would want to override AUTO for whatever reason.

Great article, which I strongly agree with. Another reason I've personally see for over-reliance on icons instead of text is it's an easier, cheaper way to satisfy localization requirements.

Not even sure why we need a parking mode for the lights now. Sounds like a legacy thing

My lights confuse me so I just leave them on all the time. Safer that way anyway

In that Porsche example, you'd just leave the knob set to AUTO and it will always do the right thing. When the wipers come on (manually or otherwise) so will the low beams, given that this is a legal requirement in many places.

At least they had the sense not to try to invent an icon for 'AUTO', to give credit where it's due. English subtitles or (better) dashboard 'tooltips' would have been a good idea, and tooltips are in fact used in quite a few other contexts.

Don't parking/marker lights generally turn on your tail lights at the same brightness as when the headlights are on? Tail lights are generally two filament bulbs. The dimmer one is the continuously-on marker light and the brighter one is for the brakes. Maybe it's different with LED-native lights? I personally use just the marker lights in the rain (and dusk) because unless I am benefiting from the headlight beams, it's just extra light pollution for oncoming cars.