Final answer:
A steady downward green arrow over a traffic lane indicates that vehicles in that lane can proceed in a specific direction, usually for a dedicated turn.
Step-by-step explanation:
A steady downward green arrow over a traffic lane indicates that the traffic in that lane is allowed to proceed in a specific direction. It is commonly used in traffic signals to indicate a dedicated turn lane, where vehicles can turn in the direction indicated by the arrow.
For example, if there is a steady downward green arrow over the rightmost lane of a road, it means that vehicles in that lane can make a right turn while other lanes follow different traffic rules.
This signal is important for controlling traffic flow and ensuring safe and efficient movement of vehicles on the road.