[puffyvolvo]

While I initially would prefer the idea of more street trees the nagging voice in the back of my head continues to worry about unintended consequences.

A big one regarding more trees is more maintenance, you've already pointed out how terrible maintenance can be, and lawns alone are an incredible example of just how inefficient we handle plants in the name of some arbitrary aesthetic, tons of water wasted, many hours spent trimming things to some ideal size that turns out to be terrible for the plant itself, etc.

Of course my paranoia doesn't ignore cool pavements either; the reflectivity does bring some mild worries: some skyscrapers are known to cause large amounts of concentrated reflective heat, but those are due to the more mirror-like reflective properties of glass rather than the diffusive matte grey/whites of these pavements. I also worry about visibility, could we end up having a "snow blindness" effect? Would driving be affected as the harsh unnatural dark contrast of a typical road is very easy to spot compared to...everything else. I'm ofcourse aware not all roads are this black but you can't deny bright yellows and whites of road markers on a deep black road would be easier to pick up on than on a greyish road.

[NumberWangMan]

I agree with you on the matter of lawns, but not on street trees. Yes, they require maintenance, but they make a massive difference in the comfort of people walking, which is a big factor in people deciding to walk rather than drive, as well as increasing the general attractiveness of the area to potential residents who might otherwise live in a car dependent suburb of something. When you add up all the benefits, I'd consider street trees to be analogous to brushing your teeth-takes a bit of effort but the cost of not doing it is far greater.

This of course applies mostly to areas that are hot for a good portion of the year.

And I have the same concerns as you about the reflective pavement.

[BurningFrog]

One logical answer is "Artificial trees".

That is, constructed shade structures that provides shade without being unpredictable living things.

There are probably real problems with that approach too. What are they?

[sa1]

Trees also affect weather on a larger scale by transpiration - I'm just pointing out shade structures are not directly comparable.

Note that buildings are also shade structures but they contribute to the heat island effect.

[clairity]

mainly cost. trees are cheap (~$100-300) compared to tarps or other fixed shade options, though i'm down for any and all shade. for comparison, bus shelters are estimated to cost $5K-30K each ( https://pedestrianobservations.com/2019/04/12/little-things-... ).

[Retric]

That ignores a lot of costs such as leaf collection. Trees are only cheap if you don’t need to worry about stuff around them.

[clairity]

i mean, leaf collection for street trees is like 10-15 minutes of work a week during growing season? you could give a neighborhood kid $5 to do that along with the occasional watering (we actually have a volunteer organization in my neighborhood that does this, though not weekly). artificial shelters need cleaning/maintenance too, so it doesn't seem to be a significant net difference.

[Retric]

This is where it’s more open to interpretation. Wet leaves on pavement are a significant fall hazard and should be removed more frequently, but that’s optional.

Tree trimming and eventually removal can cost 500-1000+$ for older trees which you eventually need to do to avoid having limbs and eventually trees fall on nearby cars. Roots damage local pavement again if you let the trees grow large enough. They also start taking up significant space requiring much wider sidewalks.

Of course you can remove them and add new trees regularly, but that’s another cost and tends to upset locals. Etc. granted his is usually in comparison to an empty sidewalk as it’s unusual to have other forms of public shade.

[koolba]

Artificial plants are like synthetic plastic grave stones, superior in almost every way to the traditional approach yet considered incredibly tacky.

[nl]

Except for the transpiration and reduction of CO2.