Opening of I-355 South Extension Tollway in Chicago in November

The Illinois Tollway is opening the I-355 South Extension in the southwest of the Chicago area soon - probably in November. The 20km (12.5 miles) of new tollroad is 2x3 lanes and runs from the southern end of the present I-355 North-South Tollway at I-55 (Stevenson Expressway) down to I-80.

The new portion of the I-355 Tollway will have five new interchanges at
- 127th Street Dupage
- Archer Avenue
- W 159th St
- US6
- I-80

The interchange at the earlier terminus with I-55 is almost completely new.

There are about a dozen bridges for cross streets over the new tollway.

Pavement of the I-355 Extension is unusual  - entirely concrete.

There is one mainline plaza with the new stretch of tollway and four pairs of ramp toll points. Tolling is a combination of 2x3 lanes of electronic tolling at highway speed on the mainline and three cash lanes each side. The ramps have dedicated cash and transponder lanes.

The major structure in the extension in generally flat countryside is a 2.1km (1.3 mile) bridge over the Des Plaines River. It has a wide flood plain and as well as the river there are two canals for barges plus rail lines. The bridge is of precast post-tensioned concrete beams and rises 27.5m (90ft) above ground level at its peak. It has 34 piers.

The bridge like the roadway has  three travel lanes and a full breakdown shoulder lane leftside and rightside in each direction.

There are noise protection walls at six locations.

The new extension will serve Will County to the southwest of Chicago, one of the fastest growing areas in Illinois, and provide a connection that improves north-south mobility between I-55 and I- 80. It will provide a more direct route between homes in Will County and areas where jobs are more plentiful to the north like the O’Hare area, improving regional productivity.

Construction work began in earnest in the spring of 2005.

Project cost was put at $730m or $6.1m/lane-km just under $9.7m/lane-mile for the 120 lane-km and 75 lane-miles. The project is on-budget, a Tollway spokesman says.

ETC has done the toll systems work for the extension as part of their larger contract on the Illinois system.

Future extensions? 

A logical further extension of the tollway is southeasterly to I-57 near Peotone and then easterly to connect with Indiana's planned Illiana Expressway, but there is currently no planning for this.

Opening date has not been determined but should be some time in November, the Tollway is saying.

TOLLROADSnews 2007-08-28