A green arrow on a lane use control signal means:

A green arrow on a lane use control signal indicates that you are permitted to use that lane. This signal conveys to drivers that they may proceed safely into the lane where the green arrow is displayed, often because the direction of travel is clear and appropriate at that time.

In contrast, a red arrow would instruct drivers not to use that lane, indicating a stop or restriction, while yellow signals generally indicate caution or a need to prepare to stop. Therefore, the green arrow clearly communicates a positive directive for lane usage, making it especially important for drivers to recognize and respond accordingly to maintain safe and effective traffic flow.