That's just OSM road data?
For my own town, it seemed to recognize it (for exampled, it filled in the correct county name) but after grinding away for some number of minutes (during which it gave a couple of "Sorry this is taking so long" messages), it said "Didn't find any roads."
For us, it shows all roads plus parking areas and trails, but with no distinction except for major roads.
Works nicely for Bethesda, MD.
It's like a limited version of OpenOrienteeringMap (which was first released in 2009)https://oomap.co.uk/global/#/new/streeto_global/
The creator is also on twitterhttps://twitter.com/oobr?lang=en
Interesting! I tried it for Rochester, NY, and it worked. Very detailed map. There seem to be some oddities. For many parking lots, it draws in all of the aisles, etc. It shows trails in city parks. That could be good or bad, because there is no obvious way to distinguish streets from trails, that I could find anyway. And it shows many driveways (longer ones) as roads.
The obvious way is to go out and field check it (or use some kind of satellite imagery). 90% of the time is typically in the drawing when you start an urban map from scratch.