Speaking

Active Traffic Management (ATM) enables agencies to dynamically manage congestion, incidents and demand using real-time data and responsive operational strategies. For safety engineers, ATM provides an opportunity to integrate operations and geometric design to enhance both safety and reliability without major reconstruction.

This presentation examines the safety and operational benefits of strategies such as part-time shoulder use, adaptive ramp metering, variable speed limits and speed harmonization. Case studies will illustrate how these tools reduce speed differentials, smooth traffic flow and improve incident response. The presentation will also address geometric refinements that complement ATM, including understanding the difference between design speed and operating speed, studying the tradeoffs of lane and shoulder widths and context-sensitive design decisions that improve safety performance.

Specific geometric evaluations, such as a practical interpretation of horizontal stopping sight distance criteria, will be explored, including the potential to modify object height assumptions (e.g., 3.5 feet instead of 2 feet) in corridors with continuous camera detection and rapid response capabilities. The safety benefits of speed harmonization in reducing speed variance and crash risk will also be highlighted.

Finally, the presentation will identify key research needs to support effective implementation, including driver compliance with variable speed limit systems, the effectiveness of rumble strips as audible departure warnings in corridors with reduced shoulder widths and the development of meaningful measures of effectiveness for adaptive ramp metering.

By aligning ATM strategies with thoughtful geometric considerations and targeted research, agencies can optimize existing infrastructure to create safer, more reliable freeway environments.