During nighttime conditions, what must be done to arrow boards?

Answer: B — They need to be reduced in brightness

During nighttime conditions, reducing the brightness of arrow boards is crucial for several reasons. Bright lights can be blinding to drivers and can contribute to glare that reduces visibility rather than enhancing it. By lowering the brightness, the arrow boards provide a clear and visible signal without overwhelming the driver’s ability to see and react to the surrounding environment. Properly adjusted brightness levels ensure that the warning signs are still effective in alerting drivers to road conditions while promoting safety for both motorists and workers in the work zone. It strikes a balance between visibility and reducing the potential for visual distractions or hazards for drivers at night.