Reconstructing Philadelphia’s Vine Street – a major at-grade artery with lights and bottlenecks at every intersection – into I-676, a limited-access highway, posed formidable challenges to the engineering team lead by Michael Baker. Cutting a swath 26 feet below a busy city while maintaining traffic for pedestrians and 80,000 vehicles per day was a complex design and construction effort that involved:
- Extensive community participation
- Fast-track design of 17 bridges, 41 retaining walls and ancillary structures
- Relocating a maze of underground utilities
- Threading the expressway under Broad and Vine, Pennsylvania’s busiest intersection, through a subway mezzanine and above an operating subway
- Excavating 1.1 million cubic yards of earth
Michael Baker managed the multi-firm team responsible for the final design of roadways and structures, relocation of underground utilities, traffic engineering, construction engineering, environmental mitigation and landscaping.
The newly-designed I-676 is a critical east-west arterial route through Center City that features four depressed lanes for high-speed traffic, six local lanes and 17 cross-street bridges. Award-winning landscaping, decorative noise walls and other “good neighbor” elements enhance the visual appeal of the urban expressway.