Well, when I lived in Royal Oak, I was too young to call it anything (and they widened Washington when I was an infant, eliminating it in front of my house.
When I lived in Rochester, we called it the “township property,” but we were out in the now disappeared Avon Township.
When we moved to Orion Township, we called it the ditch (because there were no sidewalks, but it was a ditch). However, at the same time, I started high school in Detroit, where I ran into guys from all over metro Detroit, so I have no provenance for the source of “tree lawn.”
Looking at SmackFu’s link, it is a bit surprising how many of the different terms have strong support in metro Detroit. (I would guess that the number of people from around the country who came to Detroit for jobs probably brought in a lot of terms that might have remained neighborhood-specific.)
I had never heard it called a berm in Detroit, although the link shows it being used there. (In my experience working for a landscape company, berm was used (against all etymology or logic) to refer to a raised earthen landscape feature.) Around Cleveland, berm is more typically used in place of shoulder–which makes sense, since few NE Ohio roads have anything that a Michigander would actually call a shoulder.
I may have heard easement used around Detroit, but I more frequently heard that word used (correctly) to indicate a place on one’s property where other people or entities could put a road or utilities. (I can see the logic behind easement as the place the city/county/township owns the land but the homeowner is permitted to plant grass or flowers.)
Easement or ‘boulevard’ is what I have heard it referred to around here. Devils strip I have heard used to refer to uh, well, there is this space between your-never mind. Family friendly and all that.
I’m from 12 miles east of Akron. We always called it a devil’s strip. I’m also from 35 miles south of Cleveland, but until today I’d never heard the term “treelawn.” Still haven’t; I’ve only read it.
Down here in Houston, I don’t know what they call it. I think maybe easement. But I call it a devil’s strip.