Surface Transportation

Illinois Tollway Mile Long Bridge


As part of the Central Tri-State Widening project, the Mile Long Bridge Reconstruction dramatically decreases traffic congestion all along I-294. Constructed in 1958, the original Mile Long Bridge comprises two separate bridges, northbound and southbound, with four lanes in each direction. With over 150,000 vehicles traveling over it daily, a massive widening project was necessary.

JWI is proud to have served as part of the project management team overseeing the reconstruction of both bridges, with the northbound bridge completed and operational (4430) and the southbound bridge (4431) currently in construction. Part of this current work involves demolishing the old northbound bridge and the old southbound bridge right next to it.

Each bridge includes five lanes, 27 spans supported by 26 piers, and inside shoulders serving as flex lanes. The wide-flange concrete beams weigh up to 122.5 tons and are between 106 and 187 ft long and 7.5 ft tall, the largest ever used in Illinois. We continue to provide construction oversight and inspection services for work that includes the construction of culverts under ramps and local roads, precast culverts sections and Jacked-In-Place pipe culverts, as well as temporary roadway lighting/temporary camera installations, Future ITS Installations, and Roadway Patching.

Over a hundred steel beams, each 10 ft tall and between 57 ft to 134 ft, are also involved. JWI helped oversee the complex installation of these steel bridge girders, including those crossing the Chicago Sanitary and Ship Canal. An onsite dock was built, and using a crane on a barge over the canal, steel erector crews could place and bolt the beams. Each drill shaft for the piers is 40 to 45 ft deep. The existing, soon-to-be-relocated jet fuel lines and other pipelines and utilities, including a 36-inch water main, required protection during construction.


OwnerIllinois Tollway

ClientBowman Consulting

Completion DateOngoing

MarketSurface Transportation


Project Value$400M

Services Performed

  • Project Management