South Tri-State Tollway (I-294)

159th Street Interchange Project

Project Overview

The 159th Street Interchange Project is reconstructing the 159th Street Bridge over the Tri-State Tollway (I-294) in Markham and improving traffic flow at the interchange. The project includes the construction of a new bridge, ramp repairs, roadway lighting improvements, as well as drainage and landscaping work. 

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South Loop Ramp Closure Detours

Detour Map

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Construction Update (12/17/18)

The ramps carrying traffic from westbound 159th Street to southbound I-294 and from northbound I-294 to westbound 159th Street are closed with posted detours.

159th Street
On 159th Street all traffic is shifted onto the eastbound side of the bridge and is reduced to a single lane in each direction.

Traffic is expected to remain in this configuration into 2019.

Please check the Daily Construction Alert for up-to-date closure information.

Customer Impacts

Lane closures and traffic shifts will be necessary to provide a work zone and safely accommodate construction. Whenever possible, the Tollway will use traffic shifts and shoulders to keep as many lanes open during peak hours as were available before construction. Ramp closures with posted detours will be required to complete repair work. 


The 159th Street Interchange Project will extend the life of the interchange, increase traffic capacity and provide safe and convenient travel for Tollway customers. 

Building Green

The Tollway is committed to “Building Green” and minimizing the environmental impact of construction by reducing, recycling and reusing materials. 

Work Zone Safety

The Illinois Tollway is committed to ensuring that 159th Street and the Tri-State Tollway (I-294) remain safe for both drivers and workers during construction, which is part of the agency’s overall commitment to roadway safety. 

Work zone speed limits are in effect in all construction zones 24/7 and drivers should continue to watch for changing traffic patterns and use caution, especially when workers are present. 

Visit the Tollway's Work Zone Safety page.