What type of urban road is meant for through traffic and expected to carry large volumes of traffic?

Arterial roads are designed to facilitate the movement of traffic over long distances and are intended to carry large volumes of vehicles. These roads typically serve as the main routes for through traffic, connecting different areas of the urban landscape and allowing for efficient travel between major destinations. They often feature multiple lanes and may include traffic signals at intersections, but their main function is to provide a fast and efficient means of travel through urban and suburban regions.

While expressways also handle through traffic and large volumes, they are usually designed as limited-access roads that do not have intersections at grade and may not flow through urban areas as directly as arterial roads. Service roads are intended to provide access to adjacent properties and are not meant for through traffic. Collector roads serve as transitional routes, collecting traffic from local streets and funneling it to arterial roads, but they do not have the same capacity or purpose as arterial roads. Thus, the characteristics and functions of arterial roads position them as the correct answer for this question.