Northwest Illinois bridge over the
Galena River in Galena As the highway enters Illinois across the
Julien Dubuque Bridge, it continues southeasterly for a while, paralleling the
Upper Mississippi River before turning east into the rugged country of the
Driftless Area in
Jo Daviess County, then turning flat and straight west of
Stockton and entering
Stephenson County. The
Ulysses S. Grant Home, a national landmark, fronts near the highway at the eastern edge of
Galena. The road between Dubuque and Stockton was once known as the most dangerous stretch of road because of the hills and curves flanked by cliffs and valleys. Travelers were greeted with signs reminding them to drive carefully as they entered this stretch of road. In
Freeport, US 20 is routed onto a
controlled-access freeway bypass. Between Freeport and
Rockford, the route is a four-lane
divided highway with two
traffic light-controlled intersections, at Pecatonica Road and at Winnebago Road/Elida Street. The Rockford bypass routes US 20 onto a full controlled-access freeway; it remains this way until it
overlaps Interstate 39 (I-39) southeast of downtown Rockford.
Rockford to Elgin East of Rockford, the routing of US 20 runs parallel with
I-90; US 20 serves minor cities that are not accessible from the
Jane Addams Memorial Tollway. It is a four-lane divided highway from I-39 to just east of
Belvidere; for the rest of this segment, it is a winding, rural two-lane road. US 20 travels through the downtowns of the small towns and unincorporated areas of
Garden Prairie,
Harmony and
Starks, as well as the city of
Marengo. At Starks, eastbound US 20 overlaps southbound
Illinois Route 47 (IL 47) and westbound
IL 72, forming a
wrong-way concurrency. All three routes pass beneath a railroad viaduct before separating south of Starks. Continuing east, US 20 travels through
Pingree Grove before entering the
Elgin area. Before entering Elgin, US 20 widens to a four-lane controlled-access freeway that bypasses Elgin, around the town's south end. This road is known as the Elgin Bypass.
Elgin to Indiana At the end of the Elgin bypass, US 20 takes on the name of Lake Street. US 20 has numerous high-volume intersections, including a grade-separated interchange with
IL 59. In
Hanover Park, an early-2000s reconstruction project widened lanes on the road and created a median for safer travel; east of Barrington Road/County Farm Road, the road briefly becomes six lanes for until the
Elgin–O'Hare Expressway. US 20 continues in an east-southeast direction through the town center of
Bloomingdale and becomes six lanes at the Bloomingdale–
Roselle border. It maintains six lanes through a very high traffic corridor to
I-290 and onward to
IL 53 before it returns to four lanes while serving downtown
Addison, paralleling I-290 to the north. Past
Elmhurst, the road overlaps I-290 for . US 20 continues through
Stone Park and
Melrose Park before turning south and joining
US 12/
US 45 on
Mannheim Road. In
La Grange, the combined US 12, US 20, and US 45 traveling on La Grange Road intersect with
Ogden Avenue, which carries
US 34, one of the few places where four U.S. Numbered Highways intersect. La Grange Road continues south until US 20 turns onto
95th Street eastbound with US 12. This combination later joins with
US 41, where the three routes follow Ewing Avenue and Indianapolis Boulevard, which are the last portions of US 20 prior to its crossing the state line into Indiana. ==History==