Acknowledgements
The authors of this report greatly appreciate the time, information, insights, and access provided by representatives of the following agencies:
- District of Columbia Department of Transportation.
- Texas Department of Transportation.
- Michigan Department of Transportation.
- Arkansas State Highway and Transportation Department.
- North Carolina Department of Transportation.
The authors also greatly appreciate the cooperation and assistance with data collection and archiving as provided by the following vendors:
- ASTI Transportation Systems Incorporated.
- Give 'Em A Break Safety.
- International Road Dynamics.
- Protection Services Incorporated.
- Scientex Corporation.
- United Rentals Highway Technologies.
