Illinois Department of Transportation, Milton R. Sees, Secretary Rod R. Blagojevich, Governor
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Part I Noise Fundamentals

Part II Noise Analysis

Part III Noise Abatement

Frequently Asked Questions

Glossary and Acronyms

Ground Zones


Ground zones are digitized in the computer noise model to define areas of different ground types that may affect noise levels. 

The ground types that can be specified in TNM include:

  • Pavement

  • Water

  • Hard Soil

  • Loose Soil

  • Field Grass

  • Granular Snow

  • Powder Snow

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