CO 7, from Estes Park to CO 72 near Raymond, Colorado, is part of the Peak to Peak Scenic Byway, Colorado’s oldest scenic byway. The extreme rainfall from the September 2013 flood damaged this 19-mile segment of CO 7 and CDOT used it as a detour and haul route to and from Estes Park in the aftermath of the flood, due to the closure of US 34 and US 36 from flood damage. Muller was on a team that conducted a comprehensive corridor evaluation to clearly identify the design and construction scope of work to mitigate damage caused to the highway by the flood event and the secondary damage related to the significant increase in traffic related to its us as a detour after the flood event. The work included a corridor safety and hydraulic analyses and recommendations, and the development of engineer’s estimates for cost of repairs for varying levels of flood related reconstruction requirements, including roadway overlays, partial reconstruction and full reconstruction.

The analysis identified potential improvements that included: 1) a mill and overlay and grading to restore the corridor to pre-flood conditions, 2) restoration to pre-flood conditions plus improvements for resiliency to mitigate potential future flood damage, and 3) reconstruction to full compliance with current CDOT design standards. The study produced a list of planned improvements and an accelerated design schedule with anticipation by CDOT that the design team meet or reduce the time frames identified to complete the work.

Following CDOT and consultant team review of the conceptual design, collaboration with FHWA, and FHWA concurrence on eligible improvements, the team  completed preliminary and final design for a two-phased project:

• Phase 1: Provided HMA overlay, new striping, update signing, replace guardrail and perform rock scaling for 7.25 miles of CO 7 and 1.6 miles of Business Route 7. The project also replaced 10 critical culverts, including pipe jacking at Lily Lake and Cabin Creek, and rehabilitated the bridge over St. Vrain Creek. Phase 1 was a fast-track project completed without right-of-way acquisition.
• Phase 2: Completed overlay, widening, signing, guardrail, and rock scaling for remaining 12 miles of the corridor. This phase replaced the remaining critical culverts that required ROW easements and constructed a rock catchment area for a 2-mile segment with steep rock cuts.