Navigating the Website
The Housing +Transportation (H+T®) Affordability Index website contains four tools (H+T Index map, H+T Fact Sheets, Total Driving Costs tool, and Comparison Maps) that can be accessed by scrolling down on the homepage or using the links in the header.
The header also includes links to the Data Download page and resources for learning more about the H+T Index and its applications.
The dropdown menu under the CNT logo includes links to CNT’s Location Efficiency Hub and CNT’s homepage. The Location Efficiency Hub contains information about CNT’s location efficiency solutions including web-based tools, development strategies, research and reports, and other resources that can help communities become more convenient, affordable, sustainable, and livable.
The header will remain visible as you navigate through the H+T Index website. To return to the homepage, click on the H+T Index logo.
H+T Index Map
The landing page for the H +T Index map tool asks you to enter a location. To view combined household housing and transportation costs at a location begin by entering an address. The address can be a specific street address, zip code, place, county, or Core Based Statistical Area (CBSA). The map will zoom to the address entered. If you type in a street address or zip code, the Census block group in which the address or zip code is located will be outlined and a marker will appear for the specific address.
Before the map becomes visible you will be asked if you want to take a tour of the website. The tour takes about 30 seconds and is highly recommend for new users of the H+T Index.
After you finish the tour you will see a map of Housing + Transportation costs as a percent of income at the address you entered. By clicking on the down arrow, you can also view maps of all the inputs and outputs from the transportation cost model including housing costs, transportation costs, walkability measures, transit metrics, and employment data.
When a region is selected, the default display is data modeled for the Regional Typical Household.
The Regional Typical Household assumes a household earning the median income for the region, with the average household size for the region, and the average number of commuters per household for the region. An important aspect of the H+T Index is that transportation costs are modeled for the “typical” household in a region, or the household represented by these three values.
By fixing income, household size, and commuters, the model controls for the impact of these variables on transportation costs. Differences in transportation costs are therefore a result of neighborhood characteristics and variation in the built environment. When variables are shown as a percent of income, this median income value is used. Therefore, the variable can be interpreted as the cost impact of a given location on the average household in the region.
CNT has modeled and reported data for three different household types. To change the household type, click on the circle next to the name of the household type. The modeled values for the chosen household type are displayed.
The first is the Regional Typical Household, with the assumptions described above. Second is the Regional Moderate Household, which assumes a household income of 80% of the regional median, the regional average household size, and the regional average commuters per household. Third, the National Typical Household assumes a household income of $61,828 (the national median household income), a national average household size of 2.72, and a national average number of commuters per household of 1.22.
Below the location search bar is a geography dropdown menu.
The block group ID is listed as well as the municipality, county, CBSA, etc. in which the block group is located. You can change your geography by selecting from the list. The map will zoom to the new geography that you have selected.
When you select any geography larger than a block group the legend to the left of the map becomes graphical. The histogram shows the frequency distribution of the count of block groups for each value of the given variable. The average and the range for the variable are reported below the graph. Population statistics at the bottom of the legend show the count and percentage of the population within each of the variable ranges. By clicking on the household and neighborhood tabs, you can change the chart to display statistics for households and neighborhoods. The legend also provides a link to the H+T Fact Sheet, described in detail in the following section.
Changing the Map View
The default map view after a location has been selected is housing + transportation costs as a percent of area median income. In addition to this map, there is a wide range of information that can be viewed. To bring up the complete list of available variables on the H+T Index, click on the name of the variable currently displayed on the map.
Both inputs and outputs from the transportation costs model can be mapped, and are organized into the following categories: Affordability Indices; Household Model Outputs; Greenhouse Gas from Household Auto Use; Composite Neighborhood Scores; Environmental Characteristics; Household Characteristics; and Housing Costs. Below shows how the information on the map changes when the user clicks on “Transportation Costs % of Income.”
H+T Fact Sheets
The H+T Fact Sheet tool aggregates H+T Index data to a chosen geography and provides summary statics and information in a format that is easy to print or share. To create a custom Fact Sheet enter a location.
Below the location search bar is a geography dropdown menu. The municipality is listed as well as the County, CBSA, MPO and Congressional District in which the block group is located. You can change your geography by selecting from the list. The Fact Sheet will update with information on the new geography that you have selected.
The first page of the Fact Sheet includes summary information and statistics, while the second page includes all the variables from the H+T Index Map tool aggregated to the geography of interest.
Links to share or print the Fact Sheet are at the top below the search bar.
Total Driving Costs
The Total Driving Costs tool highlights the fact that gas costs are only a fraction of total driving costs. The majority of costs are due to owning and maintaining a vehicle. The Total Driving Costs tool allows users to change gas prices to see the impact on overall transportation costs and the affordability of different locations. It utilizes the same mapping interface as the H+T Index Map.
The main map shows annual driving costs for the selected location. The default gas price used is the city average in 2013. The dollar sign is a slider which can be moved to show how changing gas prices affect annual and monthly costs; the map will update to reflect the new gas price.
The legend breaks down total auto costs into the cost of auto ownership and gas costs. Costs can be displayed monthly or annual and the map will update to reflect your selection. In addition to reporting auto ownership and gas costs, the legend shows whether costs are within a household’s recommended transportation budget.
The Comparison Maps tool features two preset side by side maps — Two Views of Affordability and Greenhouse Gas Emissions — as well as the ability to create Custom Comparisons. This tool uses the same map interface as the H+T Index Map.
Two Views of Affordability shows the traditional view of affordability — Housing Costs as a percent of income — on the left side map and the new view of affordability — Housing + Transportation Costs as a percent of income — on the right side map. This tool uses the same map interface as the H+T Index Map.
Above the maps you can choose the level of detail that you want to see, either a two color or an eight color map.
Greenhouse Gas Emissions comparison maps show annual greenhouse gas emission from household auto use. The map on the left shows emissions per acre and the map on the right shows emissions per household. This comparison illustrates that while cities and location efficient areas generally produce more total greenhouse gas emissions due to greater concentrations of households, these households on average emit fewer greenhouse gas.
Custom Comparisons allows you to select what variable to view on each map. You can also compare two different locations or household types.
The H+T Index enables individuals, planners, and policymakers to more fully grasp and act on the relationship between development patterns, transportation behavior, and household transportation costs. To further this effort, CNT makes data from the H+T Index available for free download. Data can be downloaded by Census block group, Census tract, Census defined place, county, Core Based Statistical Area (CBSA), Metropolitan Planning Organization, or US House District. A data dictionary is provided.
Registration is required to access the H+T Index data. If you are already a registered user you only need to enter your email address to access the download page.
The About dropdown menu in the header links to the following pages: About the Index, Applications for Use, FAQ, User Guide, and Glossary. The About the Index page includes an introduction to the H+T Index as well as the methodology. The Application for Use page highlights how planners, housing professionals and policymakers have used the H+T Index data and tools to support their work and lead to better outcomes. The Glossary provides definitions of variables and terms used throughout the site.