Green arrows are added to signals to indicate that drivers can travel in a particular direction, while the main lights for that approach are red, or that drivers can only travel in one particular direction. Alternatively, when combined with another green signal, they may indicate that turning traffic has priority over oncoming traffic (known as a "filter arrow"). Flashing amber arrows typically indicate that road users must give way (to other drivers and pedestrians) before making a movement in the direction of the arrow. These are used because they are safer, cause less delay, and are more flexible. Flashing amber arrows will normally be located below the solid amber.
