Illinois Department of Transportation, Erica Borggren, Acting Secretary
Patrick J. Quinn, Governor
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Part I Noise Fundamentals

Part II Noise Analysis

Part III Noise Abatement

Frequently Asked Questions

Glossary and Acronyms

Traffic Volumes

Types of traffic information input into the model include:

Peak Hourly Traffic - The highest hourly traffic volume of the day.

Average Daily Traffic (ADT) - The total traffic volume during a given period divided by the number of days in that period. Current ADT volumes can be determined by continuous traffic counts or periodic counts.

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