The structure carrying Scioto-Darby Road (County Road 22) over Big Darby Creek in Pickaway County, Ohio, known locally as the “Gantz Bridge”, was over 100 years old when the County Engineer initiated a project to replace it. The two-span, 255 foot long truss bridge was structurally deficient and functionally obsolete. The bridge’s location over Big Darby Creek – a highly protected State and National Scenic River – required diligence in project development to achieve the County’s goal of a cost effective, low maintenance replacement structure while meeting the complex environmental and permit requirements. The new 362 foot long, 3-span bridge with 0.53 miles of realigned roadway did just that.
A fundamental goal of the project was engrained into every project consideration: providing a cost-effective, low-maintenance project. Utilizing concrete I-beams reduced costs by 15% over the lifespan of the project. Utilization of the old right of way as environmental mitigation reduced new right of way acquisition and off-site mitigation costs. Avoiding extra-ordinary structure types and sizes minimized design and construction costs, and avoids specialized maintenance and inspection requirements that would be outside the capability of County forces. The awarded construction bid was $4,079,000, within 3% of the early preliminary engineering cost estimates, and 8% below the advertised estimate. Final construction costs came to $3,990,000.