The City of Chicago does not yet publish 311 service request data for tree trim requests, although I do expect that to be published soon
Meantime, I took some photos of the process here.
This tree trim operation is in the 2000 block of North Damen.
This guy has the tools of the trade: rake, shovel, ladder, tree pruner, hand pruning saw, clippers, tool belt, safety harness, nylon rope, orange traffic cones, yellow spray can (not sure what that is for)
Tree Trim Chipper Truck from Bartlett
The end result: nice crisp cuts and clear rights of way. All hail the trimmers of trees!