RDG collaborated with Calhoun-Burns and Associates (CBA) and the City of Des Moines to develop a grade-separated trail connection running underneath Fleur Drive between Des Moines' Water Works Park and Gray's Lake Park. The aesthetically pleasing design gives users a safe, attractive and well-lit passage between the two popular parks.
In addition to general safety lighting, the City intended the underpass to have a color changing system to relate to similar systems installed on nearby bridges along the same network of trails. The RDG Lighting Studio selected RGBW fixtures with a DMX head end control. The control allows for calendar settings, programmable shows, manual overrides and cellular interface for remote programming of the system. The lighting team also worked closely with the structural engineer to create a lighting trough for placement of the fixtures so as to minimize vandalism and attempt to reduce glare to both foot and bicycle traffic through the underpass. Illuminating the side walls, fixtures with 10x60 degree optics graze the structural walls of the underpass and create reflected light off the ceiling of the tunnel without visible sources. The lights are enclosed in a lighting trough created with a concrete curb and topped with a metal grating to protect the fixtures from vandalism. Due to the proximity to a flood basin, the fixtures can safely be submerged for a period of time and still remain operational after water recedes. A programmable DMX control system houses over 30 standard shows designed by city staff and is capable of over a million different static color looks.