American Institute of Certified Planners (AICP) Practice Exam

What is the primary function of Principal Arterials?

1. Provide direct access to residential areas

2. Interconnect minor arterials

3. Serve longer trips and carry high traffic volumes

4. Facilitate local traffic circulation

The correct answer is: Serve longer trips and carry high traffic volumes

The primary function of principal arterials is to serve longer trips and carry high traffic volumes. This classification of roads is designed to provide a key role in the roadway network by connecting major destinations and facilitating efficient movement across large areas. Principal arterials are typically broader roads that accommodate the needs of regional and inter-city travel, handling significant amounts of traffic, including vehicles that travel greater distances and may not have any local stopping needs. In contrast, other road classes serve different purposes. Providing direct access to residential areas is a characteristic generally associated with local streets rather than principal arterials. Interconnecting minor arterials fits the function of minor arterials themselves, which are designed to connect local streets with principal arterials while allowing some regional access. Finally, facilitating local traffic circulation is more aligned with local or collector roads, which support lower-speed travel and help manage traffic within neighborhoods. The distinct focus on long-distance travel and high traffic volumes sets principal arterials apart in the context of a roadway hierarchy.