The Location Affordability Index (LAI) consists of estimates of the combined household and transportation costs. The LAI is calculated at the Census block-group level (block groups contain 600 to 3,000 residents each) for each of the 942 Core Based Statistical Areas and at the county level for non-metropolitan counties using statistical regression modeling.

The Low Poverty Index captures the depth and intensity of poverty in a given neighborhood. The index uses both family poverty rates and public assistance receipt, in the form of cash-welfare, such as Temporary Assistance for Needy Families (TANF). Values are inverted and percentile ranked nationally. The resulting values range from 0 to 100. The higher the score, the less exposure to poverty in a neighborhood.

The primary purpose of the CHAS data is to demonstrate the number of households in need of housing assistance. This is estimated by the number of households that have certain housing problems and have income low enough to qualify for HUDs programs (primarily 30, 50, and 80 percent of median income). It is also important to consider the prevalence of housing problems among different types of households, such as the elderly, disabled, minorities, and different household types. The CHAS data provide counts of the numbers of households that fit these HUD-specified characteristics in HUD-specified geographic areas. In addition to estimating low-income housing needs, the CHAS data contribute to a more comprehensive market analysis by documenting issues like lead paint risks, "affordability mismatch," and the interaction of affordability with variables like age of homes, number of bedrooms, and type of building. Data is current as of 2/15/2016 Date of Upload: 2/22/2016

Other Bus Lines. This dataset contains other bus lines, created as part of the DC Geographic Information System (DC GIS) for the D.C. Office of the Chief Technology Officer (OCTO) and participating D.C. government agencies. Data provided by several bus companies and organizations listed bus lines supplemental to WMATA bus data. All DC GIS data is stored and exported in Maryland State Plane coordinates NAD 83 meters. METADATA CONTENT IS IN PROCESS OF VALIDATION AND SUBJECT TO CHANGE.

This is a MD iMAP hosted service. Find more information at http://imap.maryland.gov.

This service contains a variety of transit information. Data is provided by Maryland Transit Administration, Washington Metropolitan Area Transit Authority, and United States Bureau of Transportation Statistics.

DC School Attendance. This dataset shows D.C. public school attendance areas, and added to the DC Geographic Information System (DC GIS) for the D.C. Office of the Chief Technology Officer (OCTO). The boundaries were recommended by the Advisory Committee on Student Assignment and accepted by the Mayor. These new boundaries will go into effect in the 2015-16 school year and significant phasing in policies will be put into place. See DME.dc.gov for more information.

A census block is the smallest geographic unit used by the United States Census Bureau for tabulation of 100-percent data (data collected from all houses, rather than a sample of houses). The number of blocks in the United States, including Puerto Rico, for the 2010 Census was 11,155,486.

A census block is the smallest geographic unit used by the United States Census Bureau for tabulation of 100-percent data (data collected from all houses, rather than a sample of houses). The number of blocks in the United States, including Puerto Rico, for the 2010 Census was 11,155,486.

The RAILRDS layer contains Railroad features represented as lines and polylines. Attributes for this layer include the name of the railroad, and values indicating if the railroad goes onto a bridge or through a tunnel. This layer is used primarily for map visualization

A census block is the smallest geographic unit used by the United States Census Bureau for tabulation of 100-percent data (data collected from all houses, rather than a sample of houses). The number of blocks in the United States, including Puerto Rico, for the 2010 Census was 11,155,486.