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Comment by Llamamoe | Hacker News Reader

White roads could potentially be blinding, but yeah something lighter than what we do currently could be very worthwhile. It'd have much higher nighttime visibility too.

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I'm thinking about light colored roads that seem to be made of concrete. See them here and there. Seemed to be more of them when I was a kid.

Wonder if that would make a substantial difference? Much brighter than asphalt but not bright enough to bother drivers.

I was thinking you could potentially engineer them to reflect IR light, but I feel like dust and dirt would probably quickly eat into the effectiveness. The question is whether it'd really make a difference on a global scale at all.

There are materials that do what you're looking for surprisingly effectively, staying many degrees sub-ambient even in direct sunlight. (See https://onlinelibrary.wiley.com/doi/full/10.1002/eom2.12284 for example). But a roadway is a really difficult use case for a surface coating. With something like 50% of the surface area of many American cities being road or parking, there's a lot of potential room for effectively mitigating the urban heat island effect, but I think roofs are a better target. They don't have cars sitting on top of them blocking sightlines nearly as often.

> White roads could potentially be blinding

Hell I was just walking down the street a minute ago and thinking the same! It's October ffs! (It IS October right?)

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