The I-44 bridges over Range Line Road will be replaced and cloverleaf ramps will be eliminated in favor of straight, directional ramps. The project is scheduled to be finished by the end of 2013, the Missouri Department of Transportation said.
Range Line Road will be converted to a Diverging Diamond Interchange design, with traffic crossing to the left-hand side of the road at new traffic signals on either side of I-44.
During construction, all lanes of traffic on I-44 and Range Line Road will remain open during daytime hours. However, one lane will be closed in one or both directions on I-44 at various times at night -- 7 p.m. to 7 a.m.
Lane closings on Range Line Road also will take place only at night -- 7 p.m. to 7 a.m.
The lanes on I-44 will be narrowed to 10 feet wide and shifted, with the speed limit reduced to 60 mph in the work zone.
Ramps entering or exiting I-44 may have to be closed for short periods at various times.
The diverging diamond interchange is a new type of interchange that is believed to improve both safety and traffic flow compared to traditional diamond and cloverleaf interchanges. The two directions of traffic on the non-freeway road cross to the opposite side on both sides of the bridge at the freeway. It is unusual in that it requires traffic on the freeway overpass (or underpass) to briefly drive on the opposite side of the road from what is customary for the jurisdiction.
According to Wikipedia, the first of its kind in the U.S. opened in 2009 just up the road from this current project, at the intersection of I-44 and MO-13. MoDOT offers more information about this type of interchange on its website.