Central Tri-State Project: Final Deck Pour Complete on the New Northbound Mile Long Bridge


Construction crews completed the 32nd concrete pour Friday, October 2, for the new 4,800-foot-long, five-lane northbound Mile Long Bridge on the Central Tri-State Tollway (I-294).

In total, nearly 16,000 cubic yards of concrete was needed for the bridge deck and walls, an amount equal to about 1,760 fully-loaded concrete-mixing trucks. Along with the concrete, the bridge deck contains about 5.2 million pounds of stainless steel rebar, which are being used here because it resists corrosion and helps extend the life of the bridge.

To support this weight, the new bridge includes 273 precast concrete beams and 52 steel beams to build the new bridge. The largest concrete beams measured 187 feet long and 8 feet tall, with each weighing nearly 125 tons. They are the heaviest concrete beams ever used by the Tollway, and the heaviest ever produced or shipped in the Midwest.

The new bridge has 27 spans supported by 26 piers—fewer than half the number of piers supporting the existing bridge. The smaller number of piers will reduce the environmental impact on the waterways and industrial areas underneath the bridge.

Before traffic can be shifted to the new bridge, additional drainage, pavement and lighting work must be completed, along with roadway construction at the north and south end of the new bridge to tie it into the existing I-294 roadway.

The Illinois Tollway anticipates that the new northbound bridge will open to traffic in December. Construction on the new southbound Mile Long Bridge will get underway next year.

Read more about the Mile Long Bridge Project here