Illinois Department of Transportation, Erica Borggren, Acting Secretary
Patrick J. Quinn, Governor
Traveling PublicMapsProjectsRoad ClosuresNewsDoing BusinessLetting & BiddingCareers@IDOTGeneral Info

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

IDOT Privacy Statement | Illinois Privacy Information | Kids Privacy | Web Accessibility  | FOIA