U – Z

U

  • U.S. Centers for Disease Control and Prevention (CDC): A federal agency under the Department of Health and Human Services. The CDC isdedicated to protecting health and promoting quality of life through the prevention and control of disease, injury, and disability. They are committed to programs that reduce the health and economic consequences of the leading causes of death and disability, thereby ensuring a long, productive, healthy life for all people. Source: Centers for Disease Control and Prevention
  • Uncertainty Factor: Mathematical adjustments for reasons of safety when knowledge is incomplete. For example, factors used in the calculation of doses that are not harmful (adverse) to people. These factors are applied to the lowest-observed-adverse-effect-level (LOAEL) or the no-observed-adverse-effect-level (NOAEL) to derive a minimal risk level (MRL). Uncertainty factors are used to account for variations in people’s sensitivity, for differences between animals and humans, and for differences between a LOAEL and a NOAEL. Scientists use uncertainty factors when they have some, but not all, the information from animal or human studies to decide whether an exposure will cause harm to people [also sometimes called a safety factor]. Source: Centers for Disease Control and Prevention
  • Underutilized: Means an entire property or portion thereof, with or without improvements which is used only at irregular periods or intermittently by the accountable landholding agency for current program purposes of that agency, or which is used for current program purposes that can be satisfied with only a portion of the property. Source: U.S. Department of Housing and Urban Development
  • Unified Planning Work Program (UPWP): The management plan for the (metropolitan) planning program. Its purpose is to coordinate the planning activities of all participants in the planning process. Source: Federal Highway Administration
  • Uniform Relocation Assistance (URA): Most acquisitions of real property by a public agency for a Federal project or a project in which Federal funds are used are covered by the URA. If you are notified that your property will be acquired for such a project, it is important that you learn your rights under this important law. Source: U.S. Department of Housing and Urban Development
  • Unintentional Injury: Inadvertent injury resulting from events such as motor vehicle crashes, falls, drowning, and poisoning. Source: Making Healthy Places
  • Universal Design: Universal design is an approach to improve accessibility in the built environment through products and environments designed to be usable by all people without the need for adaptation. Within a residential setting, examples of universal design features include lower countertops and wide doorways for people in wheelchairs, lever faucets and door handles, and roll-in showers with handheld adjustable showerheads. These features make it possible for people to age in place. Source: HousingPolicy.org
  • Unlinked Passenger Trips (Transit): The number of passengers boarding public transportation vehicles. A passenger is counted each time he/she boards a vehicle even if the boarding is part of the same journey from origin to destination. Source: Federal Highway Administration
  • Unpaved Road Surface: Gravel/soil and unimproved roads and streets (Surface/Pavement Type Codes 20, 30 and 40). Source: Federal Highway Administration
  • Urban and Regional Planning: The design profession dedicated to envisioning, designing, and monitoring the development and redevelopment of towns, cities, and entire regions, especially for land use, transportation, and environmental decisions. Source: Making Healthy Places
  • Urban 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. Source: Centers for Disease Control and Prevention
  • 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. Source: Centers for Disease Control and Prevention
  • Urban Heat Island (UHI): An urban area that is hotter than nearby rural areas and may have increased air-conditioning costs, air pollution and greenhouse gas emissions, heat-related illness and mortality, and water usage. Source: Making Healthy Places
  • Urban Heat Island Effect: A dome of elevated temperatures over an urban area caused by structural and pavement heat fluxes, and pollutant emissions. Source: Environmental Protection Agency
  • Urban Highway: Any road or street within the boundaries of an urban area. An urban area is an area including and adjacent to a municipality or urban place with a population of 5,000 or more. The boundaries of urban areas are fixed by state highway departments, subject to the approval of the Federal Highway Administration, for purposes of the Federal-Aid Highway Program. Source: Federal Highway Administration
  • Urban Runoff: Storm water from city streets and adjacent domestic or commercial properties that carries pollutants of various kinds into the sewer systems and receiving waters. Source: Environmental Protection Agency
  • Urban Sprawl: A development pattern characterized by the following traits: 1) No boundaries; unlimited outward expansion 2) Low-density residential and commercial settlements 3) Widespread strip commercial development; sporadic or leapfrog development 4) Responsibility for land-use and zoning decisions fragmented among various jurisdictions 5) Private automobiles dominate transportation options; inconvenient or no public transportation available 6) Great differences in economic status among residential neighborhoods 7) Land-use segregated into specific zones; no mixed-use development. Source: Centers for Disease Control and Prevention
  • Urbanized Area: Area that contains a city of 50,000 or more population plus incorporated surrounding areas meeting size or density criteria as defined by the U.S. Census. Source: Federal Highway Administration
  • Urgent Public Health Hazard: A category used in ATSDR’s public health assessments for sites where short-term exposures (less than 1 year) to hazardous substances or conditions could result in harmful health effects that require rapid intervention. Source: Agency for Toxic Substances and Disease Registry
  • User Management: Defines how and which types of users can utilize a facility, such as HOV occupancy requirements, access points, barrier separation, and user fees. Restrictions may vary by time of day or day of the week. Source: U.S. Department of Transportation
  • Utilitarian Physical Activity: Physical activity that is done for the purpose of work or of moving from one destination to another, usually by walking or bicycling (cf. transportation-related activity and leisure-time physical activity). Source: Making Healthy Places

V

  • Validity: The degree to which a measurement, questionnaire, test, or study or any other data-collection tool measures what it is intended to measure. Source: Centers for Disease Control and Prevention
  • Value Pricing: Value pricing is a concept that uses monetary incentives to manage congestion during peak travel periods on tolled highways and crossing facilities. Source: U.S. Department of Transportation
  • Vanpool: Public-sponsored commuter service operating under prearranged schedules for previously formed groups of riders in 8- to 18-seat vehicles. Drivers are commuters who receive little or no compensation besides the free ride. Source: Federal Highway Administration
  • Variable Air Volume System (VAV): Air handling system that conditions the air to constant temperature and varies the outside airflow to ensure thermal comfort. Source: U.S. Environmental Protection Agency
  • Variance: Permission to depart from this development (land use) code when, because of special circumstances applicable to the property, strict application of the provisions of this development code deprives such property of privileges enjoyed by other property in the vicinity that is under identical zoning. Source: A Planners Dictionary, ed. by M. Davidson & F. Dolnick. PAS Guide 521/522
  • Vector: A living intermediary that carries an agent from a reservoir to a susceptible host. Source: Centers for Disease Control and Prevention
  • Vectorborne: Transmission of an agent by a living intermediary (e.g., tick, mosquito, or flea). Source: Centers for Disease Control and Prevention
  • Vehicle: All motorized vehicles including autos, passenger vans, pickup trucks, and other light trucks, RV’s, motorcycles and mopeds owned or available to the household. Source: U.S. Department of Transportation Federal Highway Administration
  • Vehicle Miles Of Travel (VMT): A unit to measure vehicle travel made by a private vehicle, such as an automobile, van, pickup truck, or motorcycle. Each mile traveled is counted as one vehicle mile regardless of the number of persons in the vehicle. Source: U.S. Department of Transportation Federal Highway Administration
  • Vehicle Trip: A trip by a single vehicle regardless of the number of persons in the vehicle. Source: U.S. Department of Transportation Federal Highway Administration
  • Vehicle-Miles (Highway): Miles of travel by all types of motor vehicles as determined by the states on the basis of actual traffic counts and established estimating procedures. Source: U.S. Department of Transportation Federal Highway Administration
  • Vehicle-Miles (Transit): The total number of miles traveled by transit vehicles. Commuter rail, heavy rail, and light rail report individual car-miles, rather than train-miles for vehicle-miles. Source: Federal Highway Administration
  • Vehicular Way: A route provided for vehicular traffic, such as in a street, driveway, or parking facility. Source: United States Access Board
  • Ventilation Air: Defined as the total air, which is a combination of the air brought inside from outdoors and the air that is being re-circulated within the building. Sometimes, however, used in reference only to the air brought into the system from the outdoors; this document defines this air as outdoor air ventilation. Source: U.S. Environmental Protection Agency
  • View: Narrowly defined, an extended view or prospect from a site which, many times, is as important as or more important than the site itself. Source: American Society of Landscape Architects
  • Violence: (Intentional Injury) 1) the intentional use of physical force or power, threatened or actual, against another person or against a group or community that results in or has a high likelihood of resulting in injury, death, psychological harm, maldevelopment, or deprivation; 2) threatened or actual physical force or power initiated by an individual that results in, or has a high likelihood of resulting in, physical or psychological injury or death Source: Centers for Disease Control and Prevention; Agency for Healthcare Research and Quality
  • Violence Prevention: Efforts to forestall or prevent threatened or actual physical force or power initiated by an individual that results in, or has a high likelihood of resulting in, physical or psychological injury or death. Source: Injury Prevention Network
  • Virulence: The ability of an infectious agent to cause severe disease, measured as the proportion of persons with the disease who become severely ill or die. Source: Centers for Disease Control and Prevention
  • Visitability: A movement to change home construction practices so that virtually all new homes not merely those custom-built for occupants who currently have disabilities offer a few specific features that make the home easier for people who develop mobility impairments to live in and visit. Source: Concrete Change
  • Visitable: Refers to homes that are not only accessible to guests with disabilities visiting the homes of nondisabled hosts, but to the future needs of the nondisabled residents as well. Visitability is an advocacy movement proposing that when topographically feasible, basic access to all new homes is a civil right. Access features essential to visitable homes are a zero-step entrance, accessible hallways, and bathrooms with doors wide enough for a wheelchair user to enter. Such features make a home visitable to guests with disabilities and can help a resident adapt in his/her home should the resident’s needs change due to a disability or reduced mobility. Source: AccessMaine
  • Vital Statistics: Systematically tabulated data about recorded births, marriages, divorces, and deaths. Source: Centers for Disease Control and Prevention
  • Volatile Organic Compounds (VOCs): Organic compounds that evaporate readily into the air. VOCs include substances such as benzene, toluene, methylene chloride, and methyl chloroform. Source: Agency for Toxic Substances and Disease Registry
  • Vulnerable Population: Those put at-risk by circumstances such as financial circumstances or place of residence; health, age or functional or developmental status; ability to communicate effectively; presence of chronic illness or disability; or personal characteristics. Source: Agency for Healthcare Research and Quality

W

  • Walkability: A measurement of the transportation and recreation opportunities for pedestrians, and considers pedestrian safety, convenience, and route aesthetics. Source: Centers for Disease Control and Prevention
  • Walkable Community: A community where people can walk safely. A walkable environment that has the following characteristics: Well-maintained and continuous wide sidewalks; Ramped curbs; Safe and easy street crossings; A level terrain; Well-lighted streets; A grid-patterned street design; High street connectivity; A safety buffer between pedestrians and motorized vehicles (such as trees, shrubs, streetside parked cars, green space between pedestrians and cars); A slow traffic pattern; Minimal building setbacks; Cleanliness, and; Land-use patterns characterized as mixed use with high-unit density
  • Walking School Bus: The Walking School Bus (or Bike Train) involves adult volunteers who accompany children to school, stopping at designated locations where children can join the bus or train at pre-arranged times (see more about the Walking School Bus in the Safe Streets section). Escort programs require a commitment of volunteer resources and good coordination. Source: U.S. Department of Transportation National Highway Traffic Safety Administration
  • Walking Speed: Many pedestrians travel much more slowly than 4 feet per second. Transportation industry research suggests that a more conservative walking speed–approximately 3.1 feet per second may be warranted where pedestrian use is high. Where roadways are divided by medians, a safe waiting area should be provided. If pedestrian signals must be actuated, a pushbutton should be provided at the island. It should be located within accessible reach ranges. Source: United States Access Board
  • Wastewater: The spent or used water from a home, community, farm, or industry that contains dissolved or suspended matter. Water Pollution: The presence in water of enough harmful or objectionable material to damage the water’s quality. Source: Environmental Protection Agency
  • Wayfinding: The Strategies that people use to find their way in familiar or new settings, based on their perceptual and cognitive abilities and habits. Wayfinding encompasses all of the ways in which people orient themselves in physical space and navigate from place to place. Source: Town of Chapel Hill
  • Weatherization: The process of upgrading features on an older home to improve energy efficiency. Source: Making Healthy Places
  • Wellness: Optimal state of health of individuals and groups, with two focal concerns: the realization of the fullest potential of an individual physically, psychologically, socially, spiritually and economically, and the fulfillment of one’s role expectations in the family, community, workplace, etc. Source: World Health Organization

X

  • Xeriscape: A landscape that reduces or eliminates the need for supplemental irrigation. Source: Making Healthy Places

Y

  • Years of Potential Life Lost (YPLL): A measure of the impact of premature mortality on a population, calculated as the sum of the differences between some predetermined minimum or desired life span and the age of death for individuals who died earlier than that predetermined age. Source: Centers for Disease Control and Prevention

Z

  • Zero Step Entrance: A zero-step entrance consists of a 1:12 maximum slope path to the entry door with a three-foot-wide minimum entry door.
  • Zone: The smallest geographically designated area for analysis of transportation activity. A zone can be from one to ten square miles in area. Average zone size depends on the total size of study area. Source: Federal Highway Administration
  • Zoning: The division of a city or county by legislative regulations into areas, or zones, which specify allowable uses for real property and size restrictions for buildings within these areas. Also, a program that implements policies of the general plan. Source: A Planners Dictionary, ed. by M. Davidson & F. Dolnick. PAS Guide 521/522
  • Zoning Code: The implementing legislation for policies described in a municipality’s master plan, specifying the allowable land uses. Source: Making Healthy Places
  • Zoonosis: An infectious disease that is transmissible from animals to humans. Source: Centers for Disease Control