What are floodgate messages and what are the best ways to use them?
Floodgate or broadcast messages are played at the beginning of the call (or upon reaching certain menus in the 511 system) before any other information or instructions are given. They should be used for information that is critical for travelers to know in a defined area or for a certain transportation agency. Floodgate messages should be kept short as the information may not apply to all users of the system.