I-355 is a spur route of Interstate 55, and I-55 serves as I-355's southern terminus, in extreme northern Will County. There are two toll plazas on the interstate. I-355's northern terminus is with Interstate 290 in DuPage County. In between, I-355 passes through or very near to the following communities:

• Bolingbrook
  
• Woodridge
  
• Downers Grove
  
• Lombard
  
• Glen Ellyn
  
• Addison
  
• Glendale Heights
  
• Itasca

In Chicagoland traffic reports, Interstate 290 north of the tollway and Illinois 53 north of Interstate 90 are also considered to be part of the tollway, even though they are freeways. This is because it is easier to refer to the entire north-south length as a continuous route in traffic reports instead of separating the route into its three distinct parts.

Southern Extension

The Illinois State Toll Highway Authority has plans to extend I-355 further south to Interstate 80 and perhaps to Interstate 57 and around to Interstate 65, relieving congestion on Interstate 80/94. Bidding on an excavation contract passed on November 18th of 2004 with construction beginning several days later, and barring any further legal delays the extension to Interstate 80 is to be completed by 2007.

Six interchanges will be modified or created with the southern extension, located at:

• Interstate 55
• 127th Street
• 143rd Street and Illinois State Route 171 (Archer Avenue)
• 159th Street (Illinois State Route 7)
• U.S. Highway 6 (Southwest Highway)
• Interstate 80

The extension will be 12.5 miles (20 km) long, and feature a 1.5 mile (2 km) long bridge over the Des Plaines River , the Chicago Sanitary and Ship Canal, the Illinois and Michigan Canal, Bluff Road, numerous railroads, and the Commonwealth Edison utility corridor.

External Resources

• Illinois Tollway Highway Authority