What type of communication is often used to relay information to train crews?

Two-way radio communication is fundamental in relaying information to train crews due to its immediacy and interactivity. This form of communication enables real-time dialogue between dispatchers and train operators, allowing for quick exchanges of critical information such as changes in schedules, safety alerts, and operational instructions. The ability to have both parties speak and listen facilitates clarification and ensures that messages are understood correctly, which is vital in a fast-paced and safety-sensitive environment like rail operations.

Other methods, while useful in specific contexts, do not provide the same level of responsiveness. One-way announcements can disseminate information but do not allow for instant feedback or confirmation. Text messaging systems may be practical for sending updates, but they lack the immediate interaction that two-way communication offers, and there may also be delays in receiving messages. Signal lights serve a specific purpose related to train movement and safety but do not convey detailed operational messages directly to train crews.