Traffic signals sometimes display arrows to control turns from specific lanes. A solid yellow arrow:

A solid yellow arrow has the same meaning as a yellow traffic light. When approaching a solid yellow arrow, you must reduce your speed and prepare for a red light.

• Is never used as a traffic signal.
• Has the same meaning as a circular yellow traffic light.
• Means that drivers may turn in the direction indicated by the arrow.
• Tells drivers that a green arrow is about to be shown.