In early July of 2010 during a routine inspection by MoDOT engineers damage was discovered from a settlement causing a wall to fail and the road to collapse on westbound I-470 near the interchange to westbound I-435. This made it necessary for MoDOT to immediately close the roadway.
Traffic was reouted north on both I-435 and US 71 Highway. The collapsed portion of the highway consisted of 5 lanes and handled 60,000 vehicles per day. MoDOT accelerated the design and construction process to reduce extensive delays and detours. On July 22, just 14 days after the highway closed, MoDOT awarded a $6.7 million contract to Pyramid Contractors, Inc. to repair the damaged highway with a contract wrap-up date of September 30.
HNTB Corp of Kansas City, MO provided the design for the repairs on a design-build format which allowed Pyramid to start work immediately. The contract called for removal of fill material, old pavement and walls in the collapse area and constructing of a 222 ft bridge extension.
The highway was reopened to traffic on August 27, 2010. In the end 20,000 man-hours were expended to complete the proect ahead of schedule.
Great Plains Chapter I.C.R.I.