Which measure expresses the performance of a transportation system in person-miles or person-kilometers?

Mobility is the measure that expresses the performance of a transportation system in terms of person-miles or person-kilometers. It focuses on how effectively people can move through a transport network. Mobility considers the overall movement of individuals within a given system, allowing for an analysis of both the distance traveled and the volume of people utilizing the transport facilities.

High mobility indicates that individuals can travel conveniently and efficiently to their desired destinations, making it a key performance indicator in transportation planning and engineering. This metric is crucial in understanding traffic flow and the effectiveness of transportation infrastructures, as it reflects both efficiency and reach within the transportation system.

In contrast, traffic density pertains to the number of vehicles per unit area, which does not directly account for the number of people or distance they travel. Accessibility measures how easily individuals can reach desired destinations, while connectivity reflects the degree to which different parts of a transportation system are linked and can be accessed. These concepts, while related, do not specifically measure the performance of a system in terms of distance traveled by individuals.