What color is a caution signal on railroad tracks?

A caution signal on railroad tracks is yellow. This color indicates to train engineers that they should proceed with caution. It typically means that there may be a condition ahead that requires reduced speed or an alertness to potential hazards. In the context of railroad operations, yellow signals serve as an important warning, allowing crew members to prepare for upcoming changes in track conditions, the presence of other trains, or upcoming stops or switches.

The other colors serve different purposes: red signals indicate stop, green signals indicate that it is safe to proceed, and blue signals are used for specific warning situations or to convey information related to maintenance of way activities. Understanding the significance of these colors is crucial for ensuring safe operations on the railroad.