What is the required height for reflective arrow indicators on a MUTCD directional indicator?

The required height for reflective arrow indicators on a Manual on Uniform Traffic Control Devices (MUTCD) directional indicator is 12 inches. This specification is established to ensure that the indicators are easily visible to drivers from a distance and under various environmental conditions. The 12-inch height provides adequate visibility during both day and night, enhancing road safety by alerting drivers to directional changes and important guidance on the roadway.

Reflective indicators are crucial for emergency vehicles, as they need to convey urgent information effectively, especially in low-light situations. Indicators that are too small may not be seen in time, potentially leading to dangerous situations. Therefore, adhering to the 12-inch height requirement aligns with best practices for visibility and driver awareness as described in the MUTCD guidelines.