that's a lot of car exhaust

Something I only realised today: the very ugly parking garage exposed by the viaduct removal really highlights how much crap was coming off the surface.

It's one of the small number of buildings where you have a clear single-deck exposure, because the to northern approaches hadn't merged yet. So you've got "above the deck" and "below the deck" in close proximity. Now, all else equal, if anything "above the deck" (in the sun) would be lighter, one might think, because of the bleaching effect of the sun.

But it isn't, is it?

And I'm pretty sure that garage was built in the 1980s, as part of the condominium complex at the top of it, so this is post-catalytic converters.

Yikes. Neat, eh?