What is a key characteristic of passenger cars under traffic regulations?

Passenger cars are defined under traffic regulations primarily by their ability to transport a certain number of people. Specifically, they are vehicles designed to accommodate a maximum of up to 10 individuals, including the driver. This classification allows for various types of vehicles, such as sedans and hatchbacks, to be recognized as passenger cars because they fit the capacity criteria.

This characteristic emphasizes the role of passenger cars in personal and family transportation, accommodating a diverse range of uses while maintaining safety standards. Other vehicle classifications, like buses or vans, may be designed for different purposes and capacities, underscoring the specific definition of a passenger car within the regulatory framework.

The maximum speed limit, student transport limitation, or restrictions to city travel do not define the fundamental nature of a passenger car. Thus, the specific focus on passenger capacity is what sets this option apart as the correct answer.