How much does the barrier flare rate decrease for speeds below 60 MPH?

The correct answer indicates that the barrier flare rate decreases at a ratio of 2:1 for every 5 MPH when speeds are below 60 MPH. This is significant because it highlights how lower speeds influence the effectiveness of traffic control devices, particularly in how they manage driver behavior and perceptions of safety.

The rationale behind the 2:1 decrease reflects studies and practices that show as vehicle speeds reduce, the required sight distance and overall effectiveness of the barrier flare need to be adjusted to maintain safety and efficiency. The 2:1 ratio establishes a clear, measurable standard that helps traffic control supervisors design and implement effective traffic control measures that adapt to varying speed conditions on the road.

Understanding this ratio is essential for ensuring that traffic flow is safely managed, particularly in construction zones or areas requiring special attention due to potential hazards. By applying the 2:1 principle for every 5 MPH decrease, supervisors can better plan and adjust the spacing and type of barriers used, which contributes to safer driving environments as traffic speeds lower.