Final answer:
A dashed white line on multi-lane highways indicates that the lane is used for changing lanes or overtaking other vehicles.
Step-by-step explanation:
A dashed white line on multi-lane highways indicates that the lane is used for changing lanes or overtaking other vehicles. Drivers are allowed to cross over a dashed white line when it is safe to do so. However, they should exercise caution and always check for other vehicles before changing lanes. This line serves as a guide to help maintain order and safety on the road.