The design called for the rockery wall to be sourced from locally quarried stone and incorporated into geosynthetic reinforced-soil abutments, with galvanized mesh on the exterior providing a natural appearance. When a mining permit for the original source of embankment backfill could not be acquired in time, the project team quickly found an alternative supply source in a neighboring county. Along with helping keep the project on schedule, the replacement source material was of such high quality that it was used for road base as well.

Photo courtesy City of Fort Collins

All construction activities involving railroad infrastructure required advance planning and coordination to ensure on-track safety protection for crews and to avert disruptions to freight movement. Advanced planning was especially important to overpass substructure, superstructure and rockery wall elements that were located within 25 ft of the railroad right-of-way. Work windows or track curfews were coordinated with the railroad up to eight weeks in advance. The city of Fort Collins estimated that the overpass would save motorists 32,000 gallons of fuel a year and lower emissions. The project is registered with the Sustainable Transport Council and is on track to be certified by Greenroads, a nonprofit that advances sustainability education and initiatives for transportation infrastructure.