A green light that has been green for an extended period is best described as

• A. It will become red immediately
• B. It will stay green longer
• C. It is stale and likely to turn yellow
• D. It means you may proceed without caution

Answer: (C)

A green light that has lasted longer than usual is signaling that the green phase is about to end. This is often described as a stale green—the light has been green too long and is likely to change soon, usually to yellow to warn drivers. The idea is that traffic signals cycle, and after a lengthy green, the next step in the cycle is a yellow, so you should be prepared to slow down or stop if you can do so safely. So the best description is that the green is stale and likely to turn yellow.