What do signal light configurations convey to train operators?

Signal light configurations primarily convey instructions for train operation. These signals are crucial for the safe and efficient management of train movement and help inform train operators about the status of the tracks ahead, including stop signals, proceed with caution, or clear for normal operation. This system of signals allows engineers to make informed decisions regarding speed, stopping, and other operational commands to ensure safety and adherence to schedules.

The other options do not accurately reflect the purpose of signal lights. Weather conditions are monitored separately and do not relate to signal configurations. Fuel efficiency is an operational concern but is not indicated by signal lights. Warnings about passenger behavior are also managed through different communication methods and do not pertain to what signal lights convey to train operators.