What is the minimum size cone that can be used in a 25mph or 35mph zone?

In a work zone where the speed limit is either 25 mph or 35 mph, the minimum size for a traffic cone is typically 18 inches tall. This size is designed to ensure that the cone is visible to drivers at these speeds, providing adequate warning and guidance. The visibility of the cone plays a crucial role in maintaining safety in work zones, as larger cones are more easily noticed by motorists, reducing the risk of accidents.

Choosing a cone size of 18 inches is sufficient because it strikes a balance between visibility and practicality. Cones that are too small may not be seen in a timely manner, especially at higher speeds, whereas cones that are excessively large may be cumbersome to handle and set up. Therefore, the decision to use an 18-inch cone in these scenarios is based on traffic control guidelines and best practices to ensure that drivers are alert to changing road conditions, which contributes to overall public safety.