Final answer:
Reference markers are mile markers that provide information to drivers about their location and assist with navigation on roads.
Step-by-step explanation:
Reference markers are mile markers placed along the outside shoulder to mark the edge of the roadway. They convey information to drivers about their location and provide points of reference for navigation.
Reference markers help drivers determine distances between locations on the road and assist in understanding their position with respect to a given route. They can also be used as a frame of reference, providing a set of directions for drivers to follow.
For example, reference markers may indicate that a certain town is 10 miles ahead or that a particular landmark is 2 miles to the right. They are essential for navigation and maintaining awareness of one's position on the road.