Illinois Tollway opens interchange ramps they call the Tri-Level Bridge
By Peter Samuel
The Illinois Tollway calls a refurbished pair of interchange ramps the Tri-Level Bridge. One ramp of this bridge - just reopened - takes northbound Tri-State Tollway (I-294) traffic to westbound Addams Tollway (I-90.) And there's a matching ramp that takes traffic southbound on I-294 to eastbound I-90. The second was rebuilt last year.
see aerial graphic nearby highlighting the I-294NB to I-90WB
Work consisted taking down the old 1958 deck and beams, repairing bearings and columns if needed, then placing new beams and pouring new deck on the sound old piers.
192 new precast, prestressed reinforced concrete beams were used. The bridge deck was done in a single pour across the width of the two lanes plus shoulders on each ramp, providing a stronger, lower maintenance deck than the original split deck.
Using Googlemaps measuring tool the SB-EB ramp bridging is 1920ft long and the NB-WB is 1750ft, but the Tollway says the project involves "nearly a mile of new bridge deck."
The ramps form a third level since they are direct connectors, and required to rise sufficiently high to go over two levels of roadway.
For the period of reconstruction traffic was detoured on a temporary route avoiding the interchange to allow the bridge builder to do the work more quickly and at less cost than trying to maintain traffic on the structure.
The project is ahead of schedule and will have cost the budgeted $13m when it is completed in a few weeks time.
An average 22,000 vehicles a day use the Tri-Level Bridge ramps.
Kristi Lafleur the Tollway's executive director is quoted: "We want to thank our customers for their patience during this critical reconstruction project. Closing the bridge and putting a detour in place allowed us to complete the work in half the time it would have taken had we kept the bridge open to traffic."
LANGUAGE: Chicago has a record of speaking its own kind of english, and naming interchange ramps a Bridge is an example. MUSING: Maybe it's because they're short of rivers in Chicago. River-deprived, all they've got is the odd manmade barge canal and drainage channel, so almost any kind of elevated structure becomes a Bridge?