Chicago, Norridge, and Cook County cops sit on side streets all along Montrose, Cumberland, Lawrence, & East River, The speed limit is 35 on all of them. It is hard to maintain 35 mph when you are exiting from the kennedy onto cumberland, coming out of the forest preserve on Lawrence or East River, going around the long raceway like curve that connects Montrose with East River, Speeding up to make lights, ECT. 35 makes sense in a few areas, but 40 or even 45 mph limits could be considered safe. With budget deficits to fill, don’t expect much leeway. Norridge tickets you for anything more than 5 over the limit. Chicago and Cook County might give you up to 10 over, but don’t count on it.