Iliff Avenue Corridor Construction Project
The Iliff Avenue Corridor Construction project has been completed. This $30 million project will greatly improve this important two-mile thoroughfare in Arapahoe County between South Parker Road and Quebec Street. Work started at South Parker Road, and improvements have been completed at Quebec Street. Concrete Express, Inc. was hired as the contractor for this project.
In the next few weeks, crews will be completing minor aspects of the project. Motorists may encounter intermittent lane closures as wrap-up work is completed.
Arapahoe County would like to thank businesses, motorists and residents of the Four Square Mile Neighborhood for their patience as this important project was completed. A celebration was held on Oct. 18, 2023, at the intersection of Iliff Avenue and Quebec Street. 
Major Project Milestones
The Iliff Avenue Corridor Improvements Project completed a major milestone In September 2023 with the opening of Iliff Avenue in its new alignment between South Parker Road and Wabash Street. In October 2023, Iliff Avenue's new alignment was extended to Quebec Street. The new roadway features two through lanes in each direction, acceleration and deceleration lanes, signal improvements and safer pedestrian access.
For information or questions, please email the project team at iliffave@gmail.com.
As part of the project, two dilapidated buildings at the corner of Parker Road and Iliff Avenue were demolished in the first week of November 2021. This property, which included the old Barn Store, was purchased by the County in December of 2020 for $1.76M to make improvements to the corridor. Check out pictures of the demolition.
Project Background
A Corridor Study was completed in February 2015 for the Iliff Avenue Corridor between Quebec Street and Parker Road. This study evaluated and identified improvements to transportation system mobility, safety, and reliability along the corridor. Water quality enhancements and storm water conveyance needs associated with the roadway infrastructure improvements were also evaluated and recommended.
Planned Improvements
Following the Corridor Study, Arapahoe County secured Federal funding for the design and construction of the recommended operational improvements along the corridor, which include:
- Four-lane Iliff Avenue corridor with acceleration/deceleration lanes
- Intersection modification
- Bike lanes and sidewalks between Rosemary Street and Dayton Way; multiuse path at east and west ends of corridor
- Transit stop enhancements
- Sidewalk/multi-use paths/crosswalk improvements
- Transit supportive programs
- Traffic signal progression optimization
- Signal detection/video monitoring
- Signal communication/equipment upgrades
For more details regarding the plans, see the list of corridor improvements.
View a scalable, detailed PDF of the map
Project History & Schedule
- Beginning of design phase: May 2016
- Data gathering: Spring/Summer 2016
- Preliminary design: Summer/Fall 2016
- Final design and environmental clearance: 2017-2018
- Right-of-Way Plans and Acquisitions: 2019-2021
- Construction: July 2021 to Fall 2023
Submit Comments and Questions
We appreciate your interest in the Iliff Avenue Corridor Construction Project. Comments and questions are welcome at any time and can be submitted by calling 720-239-2283 or email: Iliffave@gmail.com
