- Traffic Noise Model (TNM)
- Traffic noise and noise abatement analyses
- EIS
- High profile
- Extensive public outreach, “noise forums”
- Dense urban environment
- Exceptionally large project area
- Significant traffic impacts anticipated for adjacent land
- Wetlands, floodplains
- Natural resources, vegetation survey
Challenge
The Interstate 290 (I-290) Eisenhower Expressway improvement project, involving reconstruction and/or upgrades for the congested, 50-year-old multi-modal corridor, has a long history and has proceeded in phases commensurate with available funding. Public scrutiny of the project is high, particularly for the traffic noise. The high-profile nature of the project, dense urban development through which the project corridor extends, and length of the project corridor—from the western Chicago suburbs to downtown Chicago—added complexity to the project’s traffic noise analysis.
Solution
The scope of our analysis was massive. Over 10,000 individual receptors were studied. Four project alternatives were examined for traffic impacts, and then the preferred alternative was studied for traffic impacts as well as noise abatement analysis. Based on public comments, sensitivity analyses in particularly dense residential areas and for a nearby Chicago Parks District property were completed to determine the traffic noise consequences of various alternatives. Nearly all land adjacent to the I-290 study corridor was found to have traffic impacts in the future condition. Of 92 noise walls analyzed, 63 were deemed feasible, met IDOT’s noise reduction design goal, and were cost effective. Viewpoint solicitation packages were developed for those who would receive a noise reduction benefit from the noise walls. We also worked with the Illinois Department of Transportation (IDOT) to develop materials for “noise forums” at which votes were cast for available noise wall alternatives. With great focus from the public, alternatives changed frequently through the project in response to the Context Sensitive Solutions (CSS) process.
In addition to the traffic noise analysis, our natural resources and permitting experts completed a wetland analysis, tree survey, natural resources review, threatened and endangered species analysis, and water quality analysis, and we worked closely with the project’s engineering team to develop the floodplains analysis for the EIS.
Benefit
GZA’s team was uniquely capable of tackling a project of this scope and sensitivity, delivering a state-of-the-art technical report and working closely with the public and agencies throughout the noise analysis process to address heightened concerns about traffic noise impacts. Our noise expertise was augmented by the firm’s multi-disciplinary capacity, providing other key services for the EIS.
A Supplemental EIS and update to this 2019 EIS commenced in 2023.