What project/Whose project is this?

I apologize for the crappy photo. It was a split second phone attempt while driving. This was in Louisville, KY today.

It appears to be a lightweight trolley truck? It has traction motors? It appears to be delicate/light in construction and has spoked wheels. I didn't have time to see much, as the trucker was "movin' on down the road".

Mark,

It appears to be a truck for a single truck streetcar. It has roller bearings a long wheelbase and appears foreign in origin. The Minnesota Streetcar Museum restored a Duluth single truck car with a similar truck. I believe theirs came from Belgium and it looks identical to this.

Yes, it does look like a Brill 21-E single truck, probably a part of the stash of Brussels, Belgium trucks that were imported by the East Troy group back in the 80s.

I'm also curious on where it's going, i.e., under which streetcar the truck will go.

Here's a shot of our Duluth No. 78 (LaClede Car Co, 1893) which rides on one of the ex-Brussels 21-Es.

Thanks!