The project involves replacing the concrete viaducts where the Purple Line crosses Greenleaf, Dempster and Grove Streets in Evanston with new steel structures, as well as new abutments, retaining walls, foundations, and new waterproofing and drainage systems. The project also includes rail tie replacement, new landscaping and lighting enhancements under the bridges.
The new bridge at Greenleaf was built adjacent to the existing viaduct over a period of 1-1/2 months. During the course of a weekend, train service was temporarily suspended to allow the existing viaduct to be demolished and the new bridge span to be rolled into place. Service was resumed by the following Monday morning.