Roadway Functional Class - Arterial, Collector, and Local скачать в хорошем качестве

Roadway Functional Class - Arterial, Collector, and Local

Functional classifications are used to group roadways that serve similar transportation needs. These needs are often seen as two conflicting objectives – access and mobility. The mobility function provides few opportunities for entry and exit which results in low travel friction from vehicle access.  Arterials provide the highest levels of mobility and low levels of access.  Interstate highways are the highest order of arterials. The accessibility function provides many opportunities for entry and exit which creates potentially higher friction from vehicle access.  Local streets provide the highest levels of access. The transition between mobility and access is designated by collector roads.  These roads provide the transition between local roads and arterials. The federal functional classification system provides additional categories which further disaggregate roadways into specific types of arterials, collectors, and local roads. Local roads represent approximately 70% of the miles of roads, but carry approximately 15% of travel volume. Conversely, interstate highways, the highest order of arterials, represent only 1 or 2% of the miles, but carry approximately 30% of travel volumes. It is important to note that some roadways are easily classified.  An interstate highway is clearly an arterial and a neighborhood street with residences every 100 feet is a local street.  However, there are areas of uncertainty at the transitions between each class as some roads may not fit neatly into one class and the road’s function may even change over time as land use and travel patterns change. #HighwayDesign #DesignControls #DanielFindley