^Northbound trailblazer at Illinois 64 in Chicago, February 2021.
Illinois Route 43 runs north-south through Chicago and some suburbs to the north and south. It lies entirely within the Chicagoland area. Illinois Route 43 serves some of the western reaches of the Chicago city limits and a wide range of suburbs, up to Waukegan in the north and Frankfort in the south. In Chicago and points south, Illinois 43 is known as Harlem Avenue; however, it's known as Waukegan Road in the northern suburbs.
Illinois 43's northern end is a partial interchange with US Route 41 by Waukegan; the northern beginning is a ramp off of US Route 41 that crosses right over Illinois 120:
As it begins, Illinois 43 southbound provides a ramp for accessing Illinois 120:
Illinois 43 crosses Illinois 137, outside of North Chicago:
As Illinois 43 crosses from Deerfield into Northbrook, it meets a partial interchange with Interstate 94 that provides access to/from the west:
Very shortly afterward, Illinois 43 crosses Illinois 68:
Near Glenview, Illinois 58 comes from the west to join Illinois 43 south:
Approaching Morton Grove, Illinois 43 trades concurrencies at an intersection where Illinois 58 leaves to the east while US Route 14 joins from the west:
After a second consecutive concurrency with US Route 14, which is rather short, that route splits with Illinois 43 to go southeast:
In Niles, Illinois 43 meets the southern end of Illinois 21:
As Illinois 43 moves into northwestern areas of the city of Chicago, it meets Interstate 90 at a full interchange:
About a block to the south, Illinois 43 meets the eastern end of Illinois 72:
Still on Chicago's Northwest Side, Illinois 43 crosses Illinois 19:
Illinois 43 crosses Illinois 64 as it enters the Forest Park area:
At Forest Park, Illinois 43 meets a single-point interchange with Interstate 290 where the ramps meet the freeway on the drivers' left side:
At Berwyn, Illinois 43 meets the eastern end of US Route 34: