Which road type is primarily meant for through-traffic rather than direct access to buildings?

The road type that is primarily designed for through-traffic rather than direct access to buildings is the secondary arterial. These roads typically accommodate higher volumes of traffic and facilitate the movement of vehicles across larger distances, connecting different areas of a city or region. Secondary arterials play a crucial role in the overall transportation network by linking major thoroughfares and providing a route that is more efficient for long-range travel.

In contrast, local streets are intended for providing direct access to residences and businesses, often featuring lower traffic volumes and slower speeds. Collector streets serve as an intermediary, gathering traffic from local streets and funneling it to arterial roads, but they are still meant to allow some direct access to properties. A branch is less commonly referenced in the context of roadway classifications and does not have a specific role in managing through-traffic in the way secondary arterials do. Thus, the focus of secondary arterials on facilitating uninterrupted movement is what distinguishes them as the correct answer in this context.