Silver Creek Interchange.

The record

The problem

A 1962 cloverleaf carrying 68,000 vehicles a day had run out of capacity, out of deck life, and out of patience from every commuter in the northeast metro. The agency chose CM/GC delivery so the builder could shape phasing before the design was frozen, and selected Crossgrade on qualifications and preconstruction fee. Everything on this page, like everything on this site, is illustrative fiction, but the delivery logic is the real pitch.

Preconstruction

Fourteen months in the room with the designer, running phasing options against traffic models and constructability against the ground. The decisive move came early: shifting the new eastbound bridge alignment nine feet north let us build the entire structure off-line while traffic stayed on the old deck, deleting two full closures and roughly five months of night work from the baseline concept. Our earthwork model balanced 640,000 cubic yards on site, and our risk register priced the two utilities nobody had mapped, both of which we found exactly where we feared.

The build

Thirty-four months, four traffic configurations, zero full mainline closures. Drilled shafts to 80 feet, 9,400 cubic yards of structural concrete, and 1.6 miles of 60-inch storm trunk installed under live lanes. Girder sets ran as planned night picks with ten-minute rolling holds. Weekly drone flights published earthwork quantities against the design surface, and the same dashboard went to the agency, the designer, and our own foremen, one set of numbers for everyone.

The result

Open to traffic 26 days ahead of the contract milestone, final cost 1.8 percent under the GMP with the balance of contingency returned to the agency's program. Ride quality earned incentive on every mainline segment. The agency's project engineer put it simply: the traveling public never saw our best work, which is exactly how interchange reconstruction should go.