4500 South Bridge Replacement (2007)
The 4500 South bridge over I-215, built in 1971, was so deteriorated that UDOT replaced it in 2007. Crews built the new 1,600-ton span beside the old one, then closed I-215 for 53 hours over a single weekend and rolled the bridge into place with self-propelled modular transporters.
I-215 reopened by Monday morning and the bridge returned to traffic 10 days later. UDOT estimated it saved about $4 million in driver costs versus a long detour.
The job became a national showcase for accelerated bridge construction and a model for replacing aging bridges without months of closures.
Same freeway, same region, same 1970s-era bridges. It shows Utah's appetite for fast replacement, and the contrast with today's two-year corridor rebuild, which bundles 30 bridge fixes with pavement and lane work.
