The City and County of Broomfield selected Muller to provide conceptual and final design services for this roadway improvement and beautification project along the border between Broomfield and Westminster. This project widened Lowell Boulevard from West 120th Avenue to Midway Boulevard from a two-lane roadway to a four-lane roadway with striped medians and left turn lanes. The project also undergrounded electrical lines and added detached sidewalks and other pedestrian amenities.

A major element of this project was the crossing of Lowell Boulevard over the Nissen Tributary to Big Dry Creek. The existing crossing was severely undersized for the floodplain, resulting in overtopping of the roadway. Additionally, Broomfield and Westminster had recently begun improvements on the Metzger Farms Open Space just east of the project area. As part of these improvements, a grade-separated crossing of Lowell Boulevard was desired. Muller’s engineers combined the improved hydraulic and pedestrian crossings into a single structure, consisting of a two-span precast arch bridge on deep foundations. Bridge monuments, concrete stains, pedestrian railings, formliners, and lighting were selected to enhance the beauty of the open space corridor and improve pedestrian experience.

In addition to the Lowell Boulevard bridge, Muller’s engineers also designed trail retaining walls, cast-in-place and Mechanically Stabilized Earth (MSE) retaining walls for the roadway approaches to the bridge, and a low flow crossing just downstream of the bridge.