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I-25 and Arapahoe Interchange
The Environmental Assessment has been extended
to December 2011

The project schedule has been extended to be completed by December 2011 to allow sufficient time to complete neighborhood traffic analyses once school is back in session, and to complete traffic analysis at the interchange following completion of CDOT’s interim improvements project. Installation of directional signs and removal of construction traffic controls are anticipated by the end of September. Traffic counts will then be conducted and analysis completed to "benchmark" the benefits of the interim operational improvements.

The next public meeting is scheduled for the end of January/beginning of February 2011.



Sign up for I-25/Araphoe Interchange email notifications!


Get Up-to-date Information from the Environmental Assessment Project Website

Read Project Newsletter # 1

Frequently asked questions on the Environmental Assessment Process.


Overview

Arapahoe Road (SH 88) provides the major east-west travel link from the southeast metropolitan area to employment and retail centers along I-25, including the Denver Tech Center (DTC).

For some time, the interchange at I-25 and Arapahoe Road has experienced heavy volumes of traffic and increased congestion.  The TREX Project that widened I-25 and built light rail to the Southeast Metro Area did not provide any operational improvements to the Arapahoe interchange.  Several studies have taken place to chart the future of the interchange including the Arapahoe Road Corridor Study and the I-25/Arapahoe Road Interchange System Level Feasibility Study. 

In 2009, a combination of federal and local funding became available to perform an Environmental Assessment on the interchange to help plan a design that would aid in congestion mitigation and that would be in the best interests of all the communities involved.   An Environmental Assessment is largely a public process with input from a wide range of experts and residents of the affected area.  The lead agency on the Environmental Assessment is Arapahoe County.  Well-known transportation consultants David Evans and Associates, Inc. are consulting on the project.

Additionally, the local jurisdictions involved (Arapahoe County, Centennial, and Greenwood Village) have been pursuing federal transportation funding for rebuilding the interchange.  This I-25 and Arapahoe Road Coalition has visited the Colorado Congressional Delegation and key committee members to talk about the funding needs for the interchange. A Washington Firm represents the Coalition and works with Congress on a weekly basis.

Arapahoe Road Corridor Study
Current and projected traffic volumes and increasing traffic congestion along Arapahoe Road prompted Arapahoe County, and the Cities of Centennial, Greenwood Village, Foxfield, and Aurora to initiate a corridor transportation study to address regional mobility and local accessibility needs now and well into the future.  A part of the corridor study looked at future solutions to the traffic congestion at the interchange of I-25 and Arapahoe Road.  A Final System Level  Feasibility Study was completed in June 2008
.

Arapahoe Road Corridor Study

System Level Feasibility Study

Goals for the feasibility study project included:

  • Relieve existing and future congestion along Arapahoe Road and the I-25/Arapahoe Road Interchange
  • Enhance regional mobility and local accessibility
  • Improve the operations and safety of Arapahoe Road, which is operating at more than capacity and I-25 which has many occurances of ramp backups on the mainline freeway

The Feasibility Study looked at a number of options for the layout of the interchange from an Improved Partial Cloverleaf to a Three-Level Diamond Interchange.  The study also looked at ways to siphon traffic from Arapahoe Road and thereby relieve congestion through the interchange.  Several locations for an underpass of I-25 were explored.  The 2005-2007 Feasibility Study included a possible new crossing of I-25 south of Arapahoe Road. Most prominent in the discussions was an underpass at East Costilla Avenue.  

System Level Feasibility Study


Environmental Assessment
The Environmental Assessment takes the System Level Feasibility Study and evaluates each option using qualitative criteria of:
  • Capacity/Operations Safety,
  • Local/Community impacts,
  • Design,
  • Environmental Impacts,
  • Economic Impacts, and
  • Cost Feasibility.

Below are links to materials that provide an excellent explanation of the process:

Citizens Guide to NEPA

The Intergovernmental Agreement (IGA) that was approved on September 21

Community Process
This Environmental Assessment process includes three public meetings over the course of the project.

In addition to these general public open houses, Centennial's Mayor and City Council have committed to hold a City-sponsored community meeting, which will include a presentation and a question and answer period, to ensure community concerns and suggestions are heard and all reasonably feasible options are examined.

The first public meeting for the EA process was held Thursday, April 15, at the Good Shepherd Episcopal Church. 230 residents attended the open house where maps and plans were on display for discussion.

Read public comments from the April meeting.

A second public meeting is planned for fall 2010.


David Evans and Associates, Inc. is responsible for outreach to the community and has established an e-mail list for anyone interested in the project.   To add your name to the list contact David Evans and Associates., Inc

Click here to see the Environmental Assessment Project Website

Centennial City Office: 13133 E. Arapahoe Road, Centennial, CO 80112, Ph: (303) 325-8000, Fax: (720) 488-0933