Court Opinions: 10th Circuit Court of Appeals Opinion from March 18

The 10th Circuit Court of Appeals

Editor’s Note: Law Week Colorado edits court opinion summaries for style and, when necessary, length.

Highlands Ranch Neighborhood v. Cater, et al.

This appeal considered whether the Colorado Department of Transportation and the Federal Highway Administration violated the National Environmental Policy Act and the Administrative Procedure Act by implementing only short-term measurements to assess the noise impact of a highway expansion project.

Colorado is expanding a state highway through the southwestern part of the Denver metropolitan area. Because the expansion project involves federal funds, the agencies must comply with applicable federal law. Specifically, NEPA regulations require the agencies to perform an environmental assessment, or EA, to determine whether noise from the expanded highway would significantly impact the surrounding areas. 

To complete this assessment, Federal Highway Administration regulations direct the agencies to follow Colorado’s state-specific guidelines for evaluating noise levels. These state-specific guidelines, found in Colorado’s 2015 Noise Analysis and Abatement Guidelines, require the agencies to identify the areas that will be affected by traffic noise, evaluate the noise using traffic noise model, or TNM, software and validate the TNM with noise measurements. 

At the heart of this dispute is step three: noise validation. The agencies determined that sections 3.2.2 and 3.3 of the Guidelines permitted validation of the TNM using short-term noise measurements. Section 3.2.2 addresses modifications to existing roadways, and it requires the agencies to perform at least two noise measurements. This section doesn’t require a particular measurement method and requires only that the measurements “best illustrat[e] the existing traffic noise environment.” Section 3.3 explains that in order to optimize the TNM’s ability to “determine the worst-hour existing noise levels and predict . . . future noise levels,” field measurements are compared to the TNM’s results. 

Taking these sections together, the agencies determined that short-term noise measurements would best represent traffic noise. After performing only short-term measurements, the agencies drafted an EA concluding that noise-mitigation measures would be needed only in select areas along the highway. The agencies then submitted the EA for public comment. During this comment period, the public raised concerns about noise mitigation. In response, the agencies conducted long-term noise measurements. But the agencies didn’t incorporate the long-term measurements in the final assessment. They noted that the results from the long-term measurements didn’t necessitate any changes. After the close of the public comment period, the agencies released a finding of significant impact, or FONSI, with respect to the traffic noise and continued with the expansion project.

The Highlands Ranch Neighborhood Coalition is a group of residents who live in the areas along the highway that won’t receive noise-mitigation measures. The coalition contended the agencies’ decision to use only short-term noise measurements violated NEPA. Specifically, the coalition pointed out that the guidelines contain a 2006 Traffic Noise Model User’s Guide and argues that section 4.0 of the user’s guide requires both short- and long-term noise measurements to validate the TNM. Accordingly, the coalition sought judicial review of the agencies’ EA and FONSI.

The district court determined that the agencies could rely on only short-term noise measurements but needed to provide a rational basis for doing so. The district court then issued two remand orders instructing the agencies to outline and support their rationale for using short-term measurements. After the second remand, the district court affirmed the agencies’ decision and determined that the user’s guide was discretionary “by its own terms.” Thus, the agencies need to only “consider” the user’s guide. Because the agencies showed that they considered the guide, the district court affirmed. 

The coalition appealed to the 10th Circuit Court of Appeals, challenging the agencies’ decision to use only short-term measurements on two grounds. First, it argued the decision to use only short-term measurements contravenes section 4.0 of the user’s guide. Second, it argued the agencies’ decision is not adequately supported by the record.

But the 10th Circuit noted in its opinion that the coalition did little to undermine the agencies’ decision. The coalition repeatedly notes that the agencies had to follow state-specific guidelines for noise evaluations. But the coalition doesn’t dispute that the agencies did, indeed, follow Colorado’s guidelines. As a result, the coalition’s point about state-specific guidelines does nothing to satisfy its burden of showing that the agencies acted arbitrarily and capriciously. And the 10th Circuit said the record belies this assertion anyway. 

The agencies did consider the user’s guide and they described it as a “reference document” when responding to public comments on the expansion. The 10th Circuit said the coalition inaccurately equated the agencies’ decision not to follow the user’s guide with a decision to completely ignore the guide.

Because the coalition failed to show that the agencies acted arbitrarily and capriciously by evaluating the highway noise using short-term measurements, the 10th Circuit affirmed the district court’s order approving the agencies’ decision.

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