St. Louis County released details Monday about the overhaul planned for that mess-of-an-intersection we fondly know as Hanley Road, Eager Road and Highway 40. After months of negotiations, the county is contracting with Gateway Constructors to build a $6 million “jug handle” interchange there, at the same time Gateway rebuilds the Hanley bridge over Highway 40.

In January or sooner, Hanley Road is expected to close, and for eight months (the closing will coincide with Highway 40 reopening between Ballas and I-170, and closing between I-170 and Kingshighway). The future interchange will allow drivers to make left turns without clogging up the through lanes (see drawing below). Drivers on northbound Hanley will not have direct access to Eager; they’ll turn right onto Dale Avenue, drive past the Metro parking garage, and then onto Eager. Several jug handles are on Lindbergh Boulevard, between Olive and Manchester.

For years, the county wanted to build a tunnel connecting the center lane of northbound Hanley to westbound Eager. The cost estimates shot up to $40 million to $50 million.

The controversial aspect here will be time. Rebuilding the Hanley Road overpass would have taken about six months, by Gateway’s estimate. Adding the interchange to the project will make the work last eight months. And, for a while, Hanley and Big Bend will be closed at the same time. Big Bend is scheduled to close for bridge reconstruction by June, 2008, and Hanley might not reopen until August.