ACTT Workshop: Iowa
Chapter 2: Project Details
2.1. Project Overview
The proposed improvements to the Council Bluffs Interstate system are intended to enhance mobility throughout the I-80, I-29 and I-480 corridors; upgrade the condition of the roadways; reduce traffic congestion and crashes; strengthen system linkages by making transitions between Interstates easier; correct functional design issues; and accommodate planned development. The corridor study will consider long-term, broadly based transportation improvements designed to address crucial travel issues in the project area. Once implemented, these improvements will bring the I-80, I-29 and I-480 corridors up to current engineering standards (Iowa DOT, Nebraska DOR and AASHTO) and modernize the existing roadway to accommodate future traffic needs.
2.2. Project Area
The project area is located within Pottawattamie County in Iowa and Douglas County in Nebraska. Council Bluffs, Iowa, and Omaha, Nebraska, are located across the Missouri River from one another on the east and west banks, respectively. The corridor includes approximately 18 mainline miles of Interstate and 14 interchanges (three system, 11 service). The project area includes I-80 from east of the I-480 interchange in Omaha east to US 6 (Kanesville Blvd.). It also includes I-29 from 25th Avenue to just south of U.S. 275 and I-480 from the Missouri River Bridge on the Iowa side to the I-29 interchange.
Figure 1: Project Area
2.3. Project Goals and Objectives
The Iowa DOT will be evaluating design options for the CBIS Improvements Project. The project team asked workshop participants to assist in developing proposed improvements by providing discussion on how best to:
- Provide a transportation system with enough capacity and operational efficiency to accommodate 2030 travel forecasts.
- Correct functional design issues such as left-hand exits, shoulder width, lane balance and ramp spacing as well as the operational issues associated with the interchange configurations.
- Improve the deteriorating conditions of the existing roadway.
- Address and reduce the occurrence of serious traffic crashes.
- Support existing and planned development in the project area.
2.4. Project Challenges
The Interstate system in Council Bluffs is typically used by 20,000 to 75,000 vehicles each day, of which anywhere from 11 to 25 percent are trucks. In some areas, I-80 currently carries more than twice the traffic it was designed to accommodate. Traffic on I-29 north and south of I-80 averages 20,000 vehicles per day, a figure that is expected to double by the year 2030. For the approximately two miles where I-80 and I-29 overlap, traffic is projected to increase to over 110,000 vehicles a day by the year 2030.
And the traffic counts aren't just an issue on the Interstate: several interchanges in the metro area are also carrying higher traffic volumes than they were originally designed to serve. This has resulted in congestion at numerous interchanges during peak traffic periods.
Further, most of the Council Bluffs Interstate System was constructed in the late 1960s. Although routine maintenance took place throughout the 1980s and 1990s, no major improvements have been made to the system since it was constructed. Much of the pavement and many of the bridges need to be updated and brought up to current engineering standards.
Additional challenges include:
- Access and traffic handling during construction. With so many employment and activity centers throughout the corridor, constructability and access are underlying concerns.
- Affordability. An economic and efficient design that garners community support will be vital in moving the project towards construction. The Iowa DOT has committed funds for this project; however, many other projects throughout the State are competing for these same funds.
- Construction timeframe. The projected construction timeframe is approximately 10 years. Ideas received at the ACTT workshop will be important in helping reduce that construction schedule. Public outreach, contractor coordination and community awareness will prove crucial to the overall success of the project.
2.5. Environmental Documentation
In 2001, the Iowa DOT and FHWA initiated the CBIS Improvements Project. The agencies determined that the environmental study would be conducted as a tiered, two-stage process.
Tier 1, which is complete, consisted of an examination of the overall system needs; a study of the alternatives that would satisfy these needs; and broad consideration of potential environmental and social impacts. The examination considered the following alternatives:
- No build.
- Reconstruction of all or part of the Interstate (construction alternative).
- Enhancement of alternate modes of transportation, i.e., transit and bicycle and pedestrian trails.
- Incorporation of transportation management strategies (TDM and TSM).
- Enhancements of other metro-area roadways.
- Construction of a new cross-town roadway.
An Environmental Impact Statement (EIS) was prepared for Tier 1. Based on the Tier 1 evaluation, the construction alternative has been identified as the preferred alternative, with three key element decisions in place. They are as follows:
- Construct a new I-80 Missouri River Bridge north of the existing bridge.
- Provide direct access between I-29 and West Broadway.
- Utilize the dual divided cross-section for the overlap section of I-80/I-29.
During Tier 2, the Iowa DOT will prepare more detailed NEPA documents for the five project segments identified in Tier I. The project segments are shown in figure 2 below.
Figure 2: Tier 2 Project Segments
2.6. Project Status
FHWA has signed the Tier 1 Final EIS, and the Iowa DOT has begun detailed engineering and environmental analysis of segments one through three. A Documented Categorical Exclusion (DCE) will be developed for each of the three segments following the identification of a preferred concept (expected in 2006). Final design will begin in 2007. The first construction project, the 24th Street overhead bridge, will begin in 2008. The construction of the new Missouri River Bridge will also begin in 2008, with other projects in segments two and three to follow as funding becomes available. Segments four and five will be undertaken at a later date.