Final answer:
The outside mirror provides the true picture of where other vehicles are behind you on the roadway.
Step-by-step explanation:
When driving, it is important to be aware of the positions of other vehicles behind you on the roadway. In this case, the mirror that provides you with the true picture of where other vehicles are is the outside mirror.
The outside mirror, also known as the side mirror, is located outside the vehicle on both sides. It is designed to give you a wider field of view and shows you the actual positions of vehicles behind you. The inside mirror, also known as the rearview mirror, provides a narrower field of view and may depend on the size and positioning of the mirror.