Council approves $89,200 design supplement to extend Rock Road project east on 50 Fifth Street

The Derby City Council voted 7-0 on May 13 to authorize a design supplemental with Professional Engineering Consultants (PEC) adding full paving of 50 Fifth Street South to the Rock Road reconstruction contract for an additional $89,200.

The Rock Road reconstruction design has been underway since July 2023 and will now extend east along 50 Fifth Street to serve two new subdivisions—Sky Ridge and the working-name Greenwood Village. City Engineer Alex Lane told council the change was driven by developer needs and the desire to avoid constructing temporary work that would be removed when later phases are built. The PEC design contract total will increase from $345,000 to $434,200.

Lane said the combined construction scope is now roughly $9 million; the supplemental design fee represents about 5% of that estimated construction cost, which Lane said is within typical industry ranges for design. Funding will be shared: arterial street policies assign most of the base road costs to the city while adjacent developments carry a share for additional turn lanes and frontage improvements. Lane and staff said WAMPO grants and developer petitions will cover portions of the project; the city’s policy typically results in roughly an 80–85% city share for arterial streets and a larger developer share for turn lanes and frontage.

Councilmember Engel moved to authorize the supplemental agreement not to exceed $89,200; the motion carried 7-0. Lane said construction is expected in 2026 and that the project will include a full traffic signal at Rock Road and 50 Fifth Street to replace a temporary county signal.

Council members asked about sidewalks, trail connections and how wider sidewalks/hike-and-bike improvements would be funded; staff said projects generally require developers to install standard sidewalks, with the city paying incremental costs for upgraded hike-and-bike sections.