The Chicago Circle, the nation's worst bottleneck for trucks and one of the worst for automobiles, is slated for a $384-million overhaul that could begin as soon as 2014.

The Illinois Department of Transportation (IDOT) is developing plans to relieve congestion at the 50-year-old, circular interchange, where traffic from three area expressways, including I-90,  I-94 and I-290, converge just west of Chicago's Loop.

“We're looking at a complete structural replacement and a reconfiguring of the interchange itself,” IDOT Project Manager Steve Schilke told reporters Thursday. In addition to increasing capacity, plans call for extending merge and weaving distances.

A joint venture of engineer/architect AECOM and TranSystems Corp., both of Chicago, is performing a $40-million analysis of potential improvements, with preliminary concepts ranging from widening  ramps and lanes that feed into the Circle to construction of a four-level interchange incorporating tunnels and additional ramps.

Preliminary studies indicate that additional lanes and ramps could reduce tie-ups by up to 30%. On Thursday, IDOT solicited public input on five conceptual designs.

Plans call for completion of preliminary engineering plans by spring 2013.  A construction start date is contingent on funding.

IDOT anticipates the federal government will fund 90% of project costs, with the State of Illinois funding the remaining 10%.

In addition to national, regional and local freight traffic, the Circle accommodates commuter traffic from west, south and northwest suburbs. On average, some 300,000 vehicles use the interchange every day. The Circle also is the site of more than 1,000 crashes per year.