I just moved back to the Windy City, and I'm about to have some furniture delivered. Delivery of big items here can be tricky, with the "L" tracks overhead. Some movers even sort of try to B.S. you and say their trucks can't make it to a certain part of town. Which isn't true, if they check bridge clearances-- and this map helps you do that. This map used to be found on the prior alderman's website, which is now deleted. So I'm linking to it here. Hope people find it useful.
Here is a direct link to that Google map.
Here you will find a list of all viaduct clearances in the City of Chicago.