Illinois Route 173
Illinois Route 173 is a east-west state highway that runs from Illinois Route 251 in the Rockford suburb of Machesney Park east to Illinois Route 137 in Zion near the Illinois-Wisconsin border. Illinois Route 173 is also one of the northernmost east-west state highways in Illinois. On Interstate 94 traveling south from Wisconsin, it is the second road seen which has an interchange at that location. Similarly, when traveling south/east from Wisconsin on Interstates 39/90 and U.S. Route 51, Illinois Route 173 is only the third exit into Illinois. In 2008, the entirety of Illinois 173 has been designated the '''173rd Airborne Brigade Highway'''
Route description
Illinois 173 travels across relatively hilly northern Illinois from the Rockford area to Zion. This area is more densely populated than other portions of rural Illinois. It is two lanes for over 90% of its length.In July 2007, a new interchange was constructed at Illinois 173, Interstates 39/90, and U.S. Route 51.