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

Denver, Colorado

Tsiouvaras Simmons Holderness provided roadway design for capacity and safety improvements on I-25 between Speer Boulevard and 20th Street. TSH evaluated alternative configurations of the collector/distributor road and auxiliary lanes, settling on two auxiliary lanes to southbound I-25. TSH then performed the preliminary and final design of the I-25 widening from Speer Boulevard to 20th Street. The revised auxiliary lanes along I-25 required design changes to the Speer off-ramp and the 20th Street on-ramp. The design also included changes on 15th Street in the vicinity of the new bridge, including new sidewalk connections and a new traffic signal at 15th and Central Street.

  • Analyzed several configurations for improving capacity, settling on the addition of two southbound auxiliary lanes
  • Improved lane balance between the Park Avenue and 23rd Avenue Interchanges