What are the only colors of flashing lights you will find at a railroad crossing?

• A. Red and blue
• B. Red and yellow
• C. Red
• D. Green and red

Answer: (C)

Flashing lights at a railroad crossing are specifically designed to alert drivers that a train is approaching. The only color used for these lights is red. When the red lights are flashing, it indicates that vehicles must stop in order to allow the train to pass safely. This use of red is standardized for stop signals in many traffic scenarios, ensuring consistency and safety in transportation.

Other colors mentioned, such as yellow, blue, or green, are not used at railroad crossings for the flashing lights. Yellow might be seen in other contexts, like warning signs or signals, but it does not apply to the lights at trains. Blue is typically not associated with crossings at all, and green is used for go signals in traffic situations, but not at railroad crossings. Therefore, the presence of only red lights at railroad crossings is crucial for clear and immediate recognition of the need to stop for an approaching train.