I-25 – Speer to 20th /15th Street Bridge

Denver, Colorado

The Tsiouvaras Simmons Holderness team provided traffic analysis and roadway design on I-25 between Speer Boulevard and 20th Street. TSH evaluated alternative configurations of the collector/distributor road and auxiliary lanes, with the goal of adding capacity while improving safety. The proposed design provides two southbound auxiliary lanes from 20th Street to Speer Boulevard to improve capacity by better achieving lane balance between the Park Avenue and 23rd Avenue Interchanges. The widening of I-25 to accommodate these lanes required a design that relocated the adjacent retaining walls and replaces the 15th Street Bridge. The project also includes extensive public involvement, traffic analysis, phasing design, environmental clearance, local roadway design on 15th Street and Central Street, and design services during construction.

  • Evaluated several alternatives for the collector/distributor road, adding two southbound auxiliary lanes
  • Provided guidance and support at all stages in the process, from concept development through construction to see that the project’s vision was enacted