How to build a highway: Finding, filling old mines a major part of Southern Beltway construction View Larger Image Pittsburgh Post-Gazette » A primer on how engineers find and fill abandoned mines hundreds of feet underground before building on top of them. Michelle2017-12-01T12:26:15-08:00November 27th, 2017|Highways, Pennsylvania| Share This Story, Choose Your Platform! FacebookTwitterEmail Related Posts ‘A fiasco from the beginning’ — Caltrans’ costs soar on $1.1 billion San Francisco tunnels April 10th, 2019 Getting There: Congestion pricing isn’t coming to Spokane, but these roads aren’t free and never were April 8th, 2019 Multi-billion, decade-long toll road plan gets green light, but bottlenecks loom March 12th, 2019 Northam announces selection of firms to build $3.3 billion tunnel project February 16th, 2019 Iowa drivers, rejoice: 60 years later, northern Iowa’s Highway 20 expansion is finally done October 16th, 2018 What’s Colorado Proposition 110: Sales tax increase for transportation October 12th, 2018 Transportation officials work to connect I-10 and I-19 south of Tucson October 12th, 2018 USDOT providing nearly $64B for transportation investments October 12th, 2018 Candidates for governor eye Georgia’s transportation needs October 11th, 2018