air pollution One or more chemicals, substances, or physical conditions (such as excess heat or noise) in high enough concentrations in the air to harm humans, other animals, vegetation, or materials.
bicycle friendly Possessing urban design factors that help make an area that caters to the needs of bicyclists. Factors include
o Public amenities such as bicycle racks on streets or by public buildings
o Regulations that allow riders to take bicycles on board buses, trains, etc.
o Accessibility such as the position of bicycle paths relative to roads, quality of the terrain, presence of curb cuts, etc.
o Safety features such as lighting, security measures, and protection from on-road vehicles
o Aesthetics of bicycle paths and their surrounding areas
brownfield Abandoned or underused portions of land occupied by vacant businesses or closed military structures, located in formerly industrial or urban areas. Redevelopment may be complicated by real or perceived contamination of the site.
built environment Human-formed, developed, or structured areas.
community A specific group of people, often living in a defined geographic area, who share a common culture, values, and norms and who are arranged in a social structure according to relationships the community has developed over a period of time. The term “community” encompasses worksites, schools, and health care sites.
connectivity The ease of travel between two points. The degree to which streets or areas are interconnected and easily accessible to one another. An example of high connectivity would be a dense grid pattern in a downtown area.
curb cuts A space within a curb that is cut away to create a flat area convenient for bicycles, wheelchairs, and strollers.
density The compactness of development. Common measures of density include population per acre or square mile and dwelling units per acre.
environment Everything external to people -- everything other than behavior and genetics. All conditions that affect people during their lifetimes.
feeder roads Smaller roadways that “feed” or connect traffic to larger roadways.
geographic information systems (GIS) Computer-based systems capable of integrating different types of geological and demographic information. By creating maps, one may depict an area's natural and human-made resources, including soil types, population densities, land uses, transportation corridors, waterways, street patterns, mass-transit patterns, sewer lines, water sources, and utility lines.
global warming The progressive gradual rise of the Earth's surface temperature thought to be caused by the greenhouse effect. Global warming may be responsible for changes in global climate patterns.
greenfields Newly developed commercial property on what was previously undeveloped and open space, or farmland.
greenhouse effect The process whereby a portion of the solar heat and energy traveling through the Earth’s atmosphere toward the earth's surface is prevented from radiating back into outer space by a variety of gases (e.g., water vapor, carbon dioxide, and other gases).
green space Open, undeveloped land with natural vegetation.
health A state of physical, mental, and social well-being and not merely the absence of disease and infirmity.
healthy community A community that is continuously creating and improving those physical and social environments and expanding those community resources that enable people to mutually support each other in performing all the functions of life and in developing to their maximum potential.
impermeable Incapable of permeating, absorbing, or diffusing water, thereby creating runoff.
infill development Development that takes place within existing communities, making maximum use of the existing infrastructure instead of building on previously undeveloped land.
infrastructure Supportive services such as water and sewer lines, roads, transit lines, schools, and other public services.
mixed-use development Juxtaposition of land classifications, such as residential, office, commercial, industrial, park, and flood plain within a given area. Land use is controlled by zoning ordinances that reflect political decisions often made at the local level.
modal choices Transportation options; one's preferred method of transportation, such as walking, bicycling, using an automobile, riding a bus or rail, etc.
neotraditional development Typical of pre-World War II communities, neotraditional development is characterized by urban regions comprising many cohesive neighborhoods, each with their own commercial core and linked to one another by some form of transit. While a metropolitan area has a central downtown, the many neighborhood centers provide a secondary service area that can be reached on foot from people's homes. The neighborhood centers may include retail establishments, offices, service providers, cinemas, health clubs, dense housing, and a transit hub.
New Urbanism An approach to development and redevelopment promoted by many architects, planners, and urban designers. To qualify as a "new urbanist" project, community development should meet the following criteria.
6. Rule out any development that is gated; that lacks sidewalks; or that has a branching, tree-like street system rather than a grid network.
7. Connect well with surrounding neighborhoods, developments, or towns, while protecting regional open space.
8. Rule out "single-use" developments that include only housing, retail, or office space. The various types of building should all be seamlessly integrated and include workplaces, retail establishments, and different types of housing.
9. Include a neighborhood center within easy and safe walking distance from all dwellings in the neighborhood. Buildings should be designed to make the street feel safe and inviting by having front doors, porches, and windows facing the street instead of having a streetscape of garage doors.
10. Include formal civic spaces and squares.
11. Satisfy the "popsicle test" whereby an 8-year-old in the neighborhood could walk to a store to buy a popsicle without encountering fast-moving cars.
nonpoint source Large land area such as a crop field or an urban area that discharges pollutants into surface and underground water over a large area; any pollution with a vague, diffuse point of origin is referred to as "nonpoint-source pollution."
ozone layer The protective layer of the Earth’s atmosphere, about 15 miles above the ground, that absorbs some of the sun's ultraviolet rays, thereby reducing the amount of potentially harmful radiation that reaches the Earth's surface.
Pedestrian friendly An area that caters to the needs of pedestrians (see "walkable community”).
percolation The extent to which a surface allows liquids and other substances to filter through it or seep to surrounding areas.
permeable Description of any surface that allows another substance (for example, water) to pass through it.
pervious Permeable; allows something to pass through it.
point source A single identifiable source that discharges pollutants into the environment. Examples are smokestacks, sewers, ditches, or pipes. Any pollution with a definable, specific source of origin is referred to as "point-source pollution."
pollution A change in the physical, chemical, or biologic characteristics of the air, water, or soil that can affect the health, survival, or activities of all forms of life in an unwanted way.
proximity The distance between different land uses such as residential and commercial.
quality of life Referring to an overall sense of well-being with a strong relation to a person's health perceptions and ability to function. On a larger scale, quality of life can be viewed as including all aspects of community life that have a direct and quantifiable influence on the physical and mental health of its members.
runoff Water from rain or snow that is not absorbed into the ground but instead flows over less permeable surfaces into streams and rivers.
setback The minimum distance required by zoning laws to be maintained between a building and the street or between a structure and property lines.
social capital The process and conditions of social networking among people and organizations that lead to accomplishing a goal of mutual social benefit, usually characterized by trust, cooperation, involvement in the community, and sharing.
sprawl A development pattern characterized by the following traits:
i. No boundaries; unlimited outward expansion
ii. Low-density residential and commercial settlements
iii. Widespread strip commercial development; sporadic or “leapfrog” development
iv. Responsibility for land-use and zoning decisions fragmented among various jurisdictions
v. Private automobiles dominate transportation options; inconvenient or no public transportation available
vi. Great differences in economic status among residential neighborhoods
vii. Land-use segregated into specific zones; no mixed-use development
street network or grid The patterns formed by roadways and the extent to which they are connected to each other (i.e., “connectivity”). For example,
o The traditional urban block-like grid involves a dense matrix of interconnected streets typically seen in older urban areas; many traffic options available
o The hierarchical grid, common in most suburban areas, consists of sets of dead-end streets and cul-de-sacs that feed into secondary roadways that ultimately feed into major roadways; traffic collects on main arteries.
syndemic A term invented to describe a set of linked health problems; two or more afflictions or epidemics interacting simultaneously and synergistically (together having a greater effect than would be expected by adding the effects of each); epidemic synergy contributing to excess burden of disease in a population.
TEA-21 The Transportation Equity Act for the 21st Century (TEA-21), which was enacted June 9, 1998, as Public Law 105-178. TEA-21 authorizes the federal surface transportation programs for highways, highway safety, and transit for the 6-year period 1998-2003. This law provides authorization and funding to transform outdated transportation priorities.
traditional development Similar to "neotraditional" development.
transit-oriented development (TOD) Development of commercial space, housing, services, and job opportunities close to public transportation, thereby reducing dependence on automobiles. TODs are typically designed to include a mix of land uses within a quarter-mile walking distance of a transit stop or core commercial area.
urban (or community) design An activity during which decisions are made about the geographic placement of and interaction between natural resources (e.g., topography, vegetation) and built elements (e.g., buildings, roads) in a specific area. Urban designers consider how people will perceive and interact with the human-made environment.
urban growth boundary (UGB) A line drawn around a metropolitan area, designating the limits of allowable growth. Land outside the boundary is protected from new development.
urban heat islands A dome of heat over a city that is formed as vegetation is replaced by pavement, buildings, and other structures necessary to accommodate growing populations. The surfaces of these structures absorb, rather than reflect, the sun's heat, causing surface temperatures to rise. The displacement of trees and shrubs eliminates the natural cooling effects of shading they would have provided.
urban sprawl See "sprawl."
walkable community A community where people can walk safely. A walkable environment that has the following characteristics:
o Well-maintained and continuous wide sidewalks
o Ramped curbs
o Safe and easy street crossings
o A level terrain
o Well-lighted streets
o A grid-patterned street design
o High street connectivity
o A safety buffer between pedestrians and motorized vehicles (such as trees, shrubs, streetside parked cars, green space between pedestrians and cars)
o A slow traffic pattern
o Minimal building setbacks
o Cleanliness
o Land-use patterns characterized as mixed use with high-unit density
zoning Local codes regulating the use and development of property within specific categories.
