3.3.1 Determining Context: Factors and Process
The general framework for the demarcation between various contexts is shown in
.
describes the primary characteristics of the respective context:
- Development density (existence of structures and structure types);
- Land uses (primarily residential, commercial, industrial, and/or agricultural);
- Building setbacks (distance of structures to adjacent roadways);
- Sidewalk and parking accommodations;
- Transit and freight accommodations; and
- Intersection/driveway density.
The context classification process does not rely solely on quantitative data or analysis (e.g., persons per square mile or building square footage), but can be used where broad comparative development differences are encountered. The context classification and functional class decisions become the starting point for geometric design choices because these choices address the modes to be accommodated and their interactions. The context category should be assigned based upon generally observed conditions within and among the determining factors as well as the consideration of expected future changes in land use patterns. The roadway planning and design process should take into account anticipated future context conditions that are often defined through State, regional, and local planning documents.
Functional class drives the function of the roadway, context classification drives the constraints of the roadway.
An Urban area, as defined by FHWA, has a population of 5,000 or greater (based on the latest Census data); all areas below a population of 5,000 are currently classified as rural. These areas can be seen on the
that is maintained by TPP . Per FHWA guidance, after each decennial census, TPP, in partnership with the MPOs and Districts, expand the urban areas for transportation planning purposes. This is generally completed about 3 years after the latest decennial census
In a recent effort, TPP (in collaboration with TTI) has developed layers in the
that will visually show context in a baseline year, 10-year forecast, and 20 year horizon down to the Traffic Analysis Zone (TAZ) level. These layers are based on the travel demand models trip generation forecasts for the respective MPO area. These layers will provide designers with an additional tool to help distinguish between urban core, urban, suburban, and rural contexts; the layers also have a finer degree of gradation for areas that are on the cusp between Urban Core and Urban, as well as between Suburban and Rural. This tool is located on the
under the layer (TPP_TDM_AreaType). Contact TP&P (GIS Management Section) for access credentials.
Note that a rural town does not have a specific quantitative definition and thus may reside in either an urbanized or rural area.
The subsequent sections in this chapter further describe and depict urban core, urban, suburban, rural town, and rural contexts. Note that urban core, urban, suburban, and rural town are considered “urbanized” contexts.
Context Classification | Development Density | Land Use | Setbacks | Sidewalk and Parking | Transit and Freight | Intersection / Driveway Density |
Rural | Lowest (few houses or other structures) | Agricultural, natural resource preservation, and outdoor recreation uses with some isolated residential and commercial | Usually large setbacks | No sidewalks or on-street parking | Little transit; moderate freight | 1-10/mile |
Rural Town | Low to medium (single-family houses and other single purpose structures) | Primarily commercial uses along a main street with some adjacent single-family residential | Predominately small setbacks | Some on-street parking and some sidewalks | Little transit; moderate freight | >30/mile |
Suburban | Low to medium (single- and multifamily structures and multistory commercial) | Mixed residential neighborhood and commercial clusters (includes town centers, commercial corridors, big box commercial and light industrial) | Predominately large setbacks | Some sidewalks and no street parking | Little transit; moderate freight | 10-30/mile |
Urban | High (multistory, low-rise structures with designated off-street parking) | Mixed residential and commercial uses, with some institutional, industrial, and prominent destinations | Mixed setbacks | On-street parking and sidewalks | High transit; moderate freight | >30/mile |
Urban Core | Highest (multistory and high-rise structures) | Mixed commercial, residential, and institutional uses within and among predominately high-rise structures | Small setbacks | On-street parking and sidewalks and pedestrian plazas | High transit; low freight | >30/mile |