Life in the fast lane

Illinois Tollway offers motorists “Open Roads for a Faster Future”

The $136 million reconstruction of Illinois’ South Tri-State Tollway through Chicago’s metro area is the single largest contract awarded by the Illinois State Toll Highway Authority.

Combining innovation, traditional design methods and new technology, Hanson and the Illinois Tollway completed this multi-million dollar reconstruction on schedule while maintaining traffic flow and minimizing delays to motorists.

“Thanks to an aggressive schedule and approach, the South Tri-State Tollway reconstruction project improved one of the busiest interstates in the Chicago area, putting motorists traveling the Tri-State Tollway back in the driver’s seat,” says John Nelson, P.E., Hanson project manager.

This project was part of the Illinois Tollway’s $5.3 billion, 10-year Congestion-Relief Program.

“The Tollway’s comprehensive capital program will open, rebuild, widen and extend roadways to improve our customers’ drive,” says Michael King, chief of communications for the Illinois Tollway.

The Congestion-Relief Program, also known as Open Roads for a Faster Future, includes:

• Rebuilding and restoring most of the tollway system,
• Providing congestion relief by converting mainline toll plazas to nonstop open-road tolling,
• Widening miles of existing roads, and
• Extending other roadways to accommodate the needs of growing area communities.

Significant size and scope define project

The widening and reconstruction of approximately 3.6 miles of the South Tri-State Tollway (Interstate 294) was one of the first phases of the Illinois Tollway’s program, and Hanson provided design-section engineering services.

Because of the project’s size and scope, Hanson assigned more than 50 engineers, roadway designers, traffic analysts, computer specialists and surveyors to work on facets of this complex project.

The design and construction was influenced by a challenging combination of physical, environmental, budgetary, schedule and traffic constraints.

These constraints included heavy traffic—136,000 vehicles per day, poor soil conditions, shallow bedrock adjacent to an active quarry, environmental considerations, archaeological findings, and an urban/suburban setting.

Project team, Tollway keep motorists in the loop

With the project team in place, Nelson and his colleagues began the task of improving traffic operations within the tight 3.6-mile area. They quickly learned this required making the best use of available land, maximizing space for construction while keeping traffic lanes open.

Maintaining six lanes of traffic—three in each direction—during construction was challenging.

Hanson developed innovative techniques to maintain traffic flow, including using counter-flow lanes and crossovers. These crossover lanes separated the traffic from the construction activities.
According to Nelson, conveying information to motorists and managing traffic incidents effectively were two goals the project team embraced.

“The Illinois Tollway installed one of its first dynamic message signs as part of this project to convey traffic information to motorists.

“Closed-circuit television cameras also monitored traffic operations during construction and after completion. This wireless system helped the Tollway’s staff respond quickly to traffic incidents,” adds Nelson.

These efforts helped the project team and the Illinois Tollway control traffic congestion throughout the construction zone. Drivers benefited by experiencing decreases in travel time, stress, vehicle fuel consumption and pollution, and accident risks.

Massive rock quarry dominates landscape

Throughout the 3.6-mile portion of the Tri-State Tollway, the roadway crosses the active Thornton Quarry, one of the world’s largest aggregate quarries. Part of the roadway is constructed on a 30-foot rock fill founded on a ridge located 110 feet above the quarry floor.

Outside the quarry, a large portion of the project passed through vast sections of rock, making lowering and widening the roadway challenging.

Pioneering approach saves time and money

In addition to the rock quarry, aging and heavily traveled pavement characterized the Tri-State Tollway.

To increase the pavement’s lifespan and reduce future delays caused by maintenance issues, the Hanson team recommended paving the road with 30-year continuously-reinforced concrete.

Rising construction costs were also a constant concern for the project team. Hanson developed performance specifications to address costs—reducing the design duration and accelerating the procurement process.

“Ultimately, this allowed the Illinois Tollway to procure a construction contract earlier and take advantage of better pricing,” states Nelson.

“Hanson understood the importance of developing methods of project delivery that reduced the duration of design without compromising the quality of the final improvement.

“We were pleased that the project was designed on schedule, and the bid came in nearly $14 million under the estimate,” says Jeffrey Dailey, P.E., chief engineer for the Illinois Tollway.

For more information, contact John Nelson at (630) 990-3800 or at jnelson@hanson-inc.com.

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