Pedestrians near the City of Madison’s Spring Harbor Park and Spring Harbor Middle School may now cross under busy University Avenue safely, thanks to a new pedestrian underpass. Ayres Associates was part of the design team the City retained to design the facility.
The project site is adjacent to a historic property that could not be disturbed. The design team also hoped to avoid costly relocation of a 20-inch-diameter sanitary sewer force main in the area. At the same time, the pedestrian underpass had to be as welcoming as possible to encourage use.
A U channel with retaining walls on each side was designed to minimize impacts to the historic property.The ends of the tunnel were widened to provide inviting and safe entrances. The tunnel is a drive-on configuration; traffic passes directly on top of the structure to avoid disturbing utilities at the site. A retaining wall was designed to protect the sanitary sewer force main. In all, the underpass involved 265 feet of concrete retaining walls and a 106-foot-long tunnel. The design incorporates simulated stone masonry surfaces, decorative railings, and lighting.