August 15, 2017 - Public Hearing
A public hearing was held on August 15, 2017 to discuss the proposed improvements of the I-29/I-480/West Broadway Interchange area in Council Bluffs, just north of the Union Pacific Railroad crossing to just south of the 25th Street interchange.
In an effort to keep you as informed and prepared as possible, the Iowa DOT invited the public to attend a public hearing to discuss how to help mitigate construction impacts. Project team members were on hand to answer questions or concerns from the public.
Meeting Materials
Contact us with your questions or comments. Deadline for receipt of comments is September 14, 2017; however, all correspondence received after this date will be included in the project files and reviewed as the project is developed. To submit a comment about this project, go to: http://bit.ly/Iowadot64391101.
You can also call the program office at 712-326-3712 or email us at info@CouncilBluffsInterstate.com
Traffic Noise
We received several comments surrounding highway noise on CBIS projects and how the Iowa DOT decides when and where noise walls are constructed. First, it is important to acknowledge areas within close proximity to the I29/I480 interchange do experience significant noise today. Like most urban interstates, this can be expected due to a combination of traffic growth and residential areas being planned right up to the highway.
In the case of Segment 4 (and all other CBIS projects) the DOT provides noise abatement when:
- The proposed improvements result in noise impacts which increase noise levels more than 3 dBA from existing conditions. Anything less than or equal to 3 dBA is not noticeable to the average human.
- A noise wall is an effective solution, meaning a wall will reduce noise levels significantly (5 dBA or more for a majority of the area impacted).
- A noise wall is a cost-effective solution.
The Segment 4 noise study showed the proposed elevated roadway will either reduce or have no impact on future noise levels in 50% of the area (22/44 noise receptors). In addition, 43% showed an increase of 2 dBA or less and 7% (3 receptors) showed an increase of 3 dBA. In addition, it is expected that the new pavement will be quieter than what exists today.
A noise wall is not being considered for Segment 4 because the proposed improvements do not significantly raise future noise levels over what exists today when compared to a no-build scenario.
More Information:
Iowa DOT Traffic Noise Study Information