Illinois Department of Transportation, Ann L. Schneider, Secretary
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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 SPEED


Typical Posted Speeds in Illinois

 

  • Rural Interstates
    • 65 mph (cars)
    • 55 mph (trucks)

 

  • Urban Interstates
    • 55 mph

 

Traffic speed is input into the model as the average vehicle speed.

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