Each message on a DMS shall consist of no more than how many phases?

The correct answer is that each message on a Dynamic Message Sign (DMS) shall consist of no more than two phases. Each phase in this context refers to a distinct portion of the message that conveys information clearly and effectively. Using two phases allows for the delivery of sufficient information while maintaining readability and comprehension for drivers.

This approach balances the need to communicate vital information, such as traffic alerts or instructions, without overwhelming the viewer, ensuring safety and clarity. If more than two phases were used, messages could become too complex or crowded, leading to confusion and potentially increasing the risk of accidents as drivers might struggle to take in the information quickly while navigating traffic. Thus, limiting messages to two phases enhances cognitive processing for drivers, promoting better understanding and safer driving conditions.