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Page 8
Suggested Citation:"Context Settings." National Academies of Sciences, Engineering, and Medicine. 2018. An Expanded Functional Classification System for Highways and Streets. Washington, DC: The National Academies Press. doi: 10.17226/24775.
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Suggested Citation:"Context Settings." National Academies of Sciences, Engineering, and Medicine. 2018. An Expanded Functional Classification System for Highways and Streets. Washington, DC: The National Academies Press. doi: 10.17226/24775.
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Suggested Citation:"Context Settings." National Academies of Sciences, Engineering, and Medicine. 2018. An Expanded Functional Classification System for Highways and Streets. Washington, DC: The National Academies Press. doi: 10.17226/24775.
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Suggested Citation:"Context Settings." National Academies of Sciences, Engineering, and Medicine. 2018. An Expanded Functional Classification System for Highways and Streets. Washington, DC: The National Academies Press. doi: 10.17226/24775.
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Suggested Citation:"Context Settings." National Academies of Sciences, Engineering, and Medicine. 2018. An Expanded Functional Classification System for Highways and Streets. Washington, DC: The National Academies Press. doi: 10.17226/24775.
×
Page 12
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Suggested Citation:"Context Settings." National Academies of Sciences, Engineering, and Medicine. 2018. An Expanded Functional Classification System for Highways and Streets. Washington, DC: The National Academies Press. doi: 10.17226/24775.
×
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Suggested Citation:"Context Settings." National Academies of Sciences, Engineering, and Medicine. 2018. An Expanded Functional Classification System for Highways and Streets. Washington, DC: The National Academies Press. doi: 10.17226/24775.
×
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Suggested Citation:"Context Settings." National Academies of Sciences, Engineering, and Medicine. 2018. An Expanded Functional Classification System for Highways and Streets. Washington, DC: The National Academies Press. doi: 10.17226/24775.
×
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Suggested Citation:"Context Settings." National Academies of Sciences, Engineering, and Medicine. 2018. An Expanded Functional Classification System for Highways and Streets. Washington, DC: The National Academies Press. doi: 10.17226/24775.
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8 Context Settings Overview The Expanded FCS provides five context categories to move beyond the traditional urban– rural dichotomy. Five categories allow for a more distinct or specific position along the con- textual continuum, which ranges from very little development to very highly developed. The context of a project situation can be compared to the five Expanded FCS categories in order to determine the best fit. The primary factors considered within each category are as follows: • Density (existence of structures and structure types). • Land uses (primarily residential, commercial, industrial, and/or agricultural). • Building setbacks (distance of structures to adjacent roadways). The continuum is not perfectly gradual for the determining factors among the five catego- ries, and therefore some degree of situational analysis, experience, and professional judgment is required. Furthermore, in real-world situations, discontinuities will exist even when the over- all assessment is clear. The Expanded FCS context assessment does not rely on a quantitative analysis (neither persons per square mile nor building square footage) and can be used in states with broad comparative development differences between urban cores or rural areas. These differences are largely a matter of scale and intensity (additionally, the activity patterns vary significantly). The Expanded FCS does not provide quantitative guidance for transitional areas between categories. However, transitional areas remain an important design consideration, affecting safety, function, and design detail. This issue needs to be addressed at the project level and associated treatments need to be considered at that level. The context category and roadway- type decisions become the starting point that leads to geometric design choices, because these choices address the modes to be accommodated and their interactions. A robust CSS process (involving all stakeholders) can assist the project team in understanding the various project issues and modal needs in order to develop a contextually appropriate design. Population growth and migration, along with economic expansion and geographic features, become major influences on development, which greatly influences settlement patterns. Land areas adjacent to expanding urban development are subject to significant discontinuities along the development continuum. Sporadic development of residential and/or commercial type may occur on the margin of all categories. Industry may be spotted throughout the landscape but is highly tied to available transportation facilities and skilled population. Even under the mostly static development pressure, incongruences will occur among the major factors in any road segment under consideration. Transportation professionals must assign the context category based upon generally observed homogeneity within and among the determining factors as well as consideration of expected future changes in land use patterns. The rural-to-urban-core continuum in a predominately rural state may differ significantly from the rural-to-urban-core continuum in a predominately urban state or in states that have

Context Settings 9 extremely large-scale urban areas with intensive development. For example, New York City, Chicago, Miami, Atlanta, and Los Angeles clearly have unique urban development patterns and intensities. Additionally, differences occur regionally in structural types for some uses such as housing. As an example, housing structure type can vary from the single detached structure to duplex structures to row houses to condominium multistructure complexes to medium-density low-rise apartment structures to high-density high-rise apartment structures. Some areas may not have such a variety of types or a majority of one type dependent upon the time period of development or other development factors. Agencies may need to supplement the photographs/ graphic examples of the Expanded FCS to better reflect the actual nature of the five categories in their jurisdictions. Some cases may warrant additional context categories or subcategories. Rural areas across the United States also have extreme geological differences that include mountains, swamps, plains, and desert, which hinder or significantly impede even sparse devel- opment. Poor soil conditions will also affect the potential for agricultural production in the rural area. However, even these areas may require roadways for regional or national system network connectivity. At the other end of the continuum lies the urban core, which may be largely devoid of regular traffic except at the fringes. Most urban cores encourage and facilitate pedestrian traffic with sidewalks, plazas, and pedestrian bridges. Typically, urban areas accommodate and encourage bicycle use. Urban and urban core areas have the highest volume of activity and the patterns of activity are usually complex. 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. At the state level, there are usually statewide long-range transportation plans that not only include vehicle transportation but also have modules or separate plans that address the future needs of the other users. These plans are more likely to exist in high-growth states with larger populations and larger metropolitan areas. At the regional and city/county level, there are usually finer- grained transportation plans with more specificity of corridor needs and desires for all modes. Local jurisdictions have comprehensive plans, zoning ordinances, subdivision regulations, and possibly special overlay districts that guide future context development. Some districts may have transportation/land use studies that address future corridors, and urban areas may have street design guidelines; all of which may influence future roadway context. Even for some rural roads and rural towns/villages, there are planning studies that may address a desired future roadway context. The caution here is that some plans with their varying horizons have more validity than others. Some areas grow faster than projected/planned, while others decline faster than expected/ planned. The assessment of future changes will take some reality testing with stake holders/ officials/designers/planners to determine the likelihood of future context change. Determining Context: Factors and Process Three primary factors are used to determine context for the Expanded FCS: • Density • Land uses • Building setbacks These factors are easy to identify by observing the landscape adjacent to an existing or planned roadway. Some other features such as topography and soil type, land value, population density, and building square footage can generally suggest points on the development continuum. All of these are relative to context, but the Expanded FCS does not rely on these features. The key questions to determine a roadway segment’s context category are: (1) Does it for the most part meet the category’s primary factors?, and (2) Does the landscape adjacent to the road- way look similar to the photographs/graphic examples? The Expanded FCS provides assessment

10 An Expanded Functional Classification System for Highways and Streets terminology and selected photographs/graphic views to assist in determining the most appropri- ate current and future context category of a roadway segment. The user must recall that there will be exceptions along any roadway, and these occur more often in the vicinity of urban areas. The following sections include a description and photographs/graphic examples of each category based on the primary factors outlined in Table 1. Rural The rural context category ranges from no development (natural environment) to some light development (structures), with sparse residential and other structures mostly associated with Category Density Land Use Setback Rural Lowest (few houses or other structures) Agricultural, natural resource preservation, and outdoor recreation uses with some isolated residential and commercial Usually large setbacks Rural Town Low to medium (single-family houses and other single-purpose structures) Primarily commercial uses along a main street (some adjacent single-family residential) On-street parking and sidewalks with predominately small setbacks 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) Varied setbacks with some sidewalks and mostly off-street parking Urban High (multistory, low-rise structures with designated off- street parking) Mixed residential and commercial uses, with some institutional and industrial and prominent destinations On-street parking and sidewalks with mixed setbacks Urban Core Highest (multistory and high-rise structures) Mixed commercial, residential and institutional uses within and among predominately high-rise structures Small setbacks with sidewalks and pedestrian plazas Table 1. Expanded FCS context categories and primary factors.

Context Settings 11 farms. The land is primarily used for outdoor recreation, agriculture, farms, and/or resource extraction. Occasionally a non-incorporated hamlet or village will include a few residential and commercial structures. In a rural setting, there are no or very few pedestrians, bicyclists are most likely of recreational nature, and transit is limited or non-existent. However, some of these may be present in the vicinity of a hamlet or village. Examples of commercial uses include a gen- eral store, restaurant, and filling station—these are usually located at crossroads. Setbacks for structures in rural areas are usually large but can certainly shrink in the immediate vicinity of a hamlet or village. Transit service availability is often absent but does vary widely depending on the jurisdiction. On-demand service is typically found to provide special service. Key Rural Characteristics • Lowest density (few houses or other structures). • Agricultural, natural resource preservation, and outdoor recreation uses predominate, with isolated residential and commercial structures. • Usually large setbacks or constrained setbacks due to topography. Figures 6 through 8 show photographs that exemplify the types of views seen from roads in rural areas. Photograph to the left shows a rural agricultural area under farm use. A residence and farm buildings are setback from the roadway. Farm equipment used for irrigation and fences are in the foreground. Figure 6. Rural farm use. Photograph to the left shows natural forested area. This rural area is not built upon and is not being used for agricultural purposes. Figure 7. Rural natural environment.

12 An Expanded Functional Classification System for Highways and Streets (a) Only one residential structure is seen in the top right. (b) Small-scale resource extraction with agricultural use. (c) Cattle ranch. (a) (b) (c) Figure 8. Variety of rural context settings. Rural Town The rural town category is characterized by low density (low-rise—one or two story— structures) but a concentrated development of diverse uses—residential and commercial. Rural towns are generally incorporated but have limited government services. Some excep- tionally larger rural towns may also serve as county/parish/borough seats with court houses and other government services. Rural towns usually have a roadway section that has a main street character (or even a town square) with on-street parking and sidewalks and in some cases bicycle lanes. Transit is uncommon in these areas. The diversity of use can include a variety of commercial establishments to serve the surrounding rural area. Some relatively compact residential uses can be expected and possibly schools. The setbacks for structures are relatively small. Key Rural Town Characteristics: • Low- to medium-density residential (single-family houses and other single-purpose structures). • Commercial uses predominate along main streets (ranging from lower to higher densities). • On-street parking and sidewalks with predominately small setbacks. Photographs in Figure 9 capture scenes that are typical of rural towns.

Context Settings 13 (a) (b) (a) Variety of commercial establishments along a rural town’s main street having sidewalks and on-street parking. (b) Single-family residential use on adjacent street. Figure 9. Rural town with main street. Suburban Locations classified as suburban include a diverse range of commercial and residential uses that have a medium density. The buildings tend to be multistory with off-street parking. Side- walks are usually present, and bicycle lanes may exist. Sometimes the development includes suburban town centers or commercial corridors. The range of uses encompasses health services, light industrial (and sometimes heavy industrial) uses, quick-stop shops, gas stations, restau- rants, and schools and libraries. Typically, suburban areas rely heavily on passenger vehicles, but some transit may be present. Residential areas may consist of single and/or multifamily struc- tures. Setbacks are varied. Suburban areas are usually connected and closely integrated with an urban area. In addition, suburban areas may have well-planned and well-arranged multi-uses that encourage walking and biking. Planned multi-use clusters may integrate residential and commercial areas along with schools and parks. It is important for project teams to understand the activity patterns these areas support and future development intentions. Key Suburban Characteristics • Low to medium density (single-family structures predominate with some multifamily struc- tures and multistory commercial).

14 An Expanded Functional Classification System for Highways and Streets • Mixed residential neighborhood and commercial clusters (includes town centers, commercial corridors, big box commercial and light industrial use). • Varied setbacks with some sidewalks and mostly off-street parking. The photographs in Figure 10 capture typical suburban landscapes. (a) (b) Both (a) residential and (b) commercial areas accommodate off-street parking and have perimeter sidewalks. Figure 10. Residential and commercial medium-density structures in a suburban area. Urban Urban locations are high density, consisting principally of multistory and low- to medium-rise structures for residential and commercial use. Areas usually exist for light and sometimes heavy industrial use. Many structures accommodate mixed uses: commercial, residential, and parking. Urban areas usually include prominent destinations with specialized structures for entertainment, athletic, and social events as well as conference centers and sometimes could be considered the main street of the town. Various government and public use structures exist that are accessed regularly. Streets have minimal on-street parking. Wide sidewalks and plazas accommodate more intense pedestrian traffic, while bicycle lanes and transit corridors are frequently present. Off- street parking includes multilevel structures that may be integrated with commercial or residential uses. Due to the differences in developmental scale among urban areas as well as growth demand,

Context Settings 15 urban–urban core context boundaries change over time with the urban core area expanding in high-growth situations and possibly contracting in low- or no-growth situations. Key Urban Characteristics: • High density (multistory low-rise structures with designated off-street parking). • Mixed residential and commercial uses, with some institutional industrial uses and promi- nent destinations. • Minimal on-street parking and sidewalks with closely mixed setbacks. The photographs in Figure 11 capture views of the urban landscape from roadways. (a) (b) (a) Low-rise commercial structures with minimum-width sidewalks. (b) Low-rise residential and mixed commercial structures. Figure 11. Urban mixed use. Urban Core Urban cores house the highest level of density with its mixed residential and commercial uses accommodated in high-rise structures. While there may be some on-street parking, it is usually very limited and time restricted. Most parking is in multilevel structures attached or integrated with other structures. The area is accessible to automobiles, commercial delivery vehicles, and public transit. Sidewalks and pedestrian plazas are present along with multilevel pedestrian bridges connecting commercial and parking structures. Bicycle facilities and transit corridors are typically common. Some government services are available, while other commer- cial uses predominate, including financial and legal services. Structures may have multiple uses, and setbacks are not as generous as in the surrounding urban area.

16 An Expanded Functional Classification System for Highways and Streets Urban Core • Highest density (multistory and high-rise structures). • Mixed commercial, residential, and institutional uses within and among predominately high- rise structures. • Small setbacks with sidewalks and pedestrian plazas. The photographs in Figures 12 and 13 depict street views of an urban core. Note: See Case Study 1 for a demonstration of the full range of context settings along an arterial. Figure 12. Pedestrian plaza (foreground) and hotel convention center. Figure 13. Urban core. (a) (b) (a) Highest density urban core with high-rise structures and surface transit (underground transit may also exist). Sidewalks are present with minimum setbacks and little or no on-street parking. (b) Mixed uses with a pedestrian plaza.

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TRB's National Cooperative Highway Research Program (NCHRP) Research Report 855: An Expanded Functional Classification System for Highways and Streets builds upon preliminary engineering of a design project, including developing the purpose and need. In particular, it provides additional contexts beyond urban and rural, facilitates accommodation of modes other than personal vehicles and adds overlays for transit and freight. Two case studies illustrating an application of the expanded system to actual projects are included. Accompanying the report is NCHRP Web-Only Document 230: Developing an Expanded Functional Classification System for More Flexibility in Geometric Design, which documents the methodology of NCHRP Research Report 855.

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