Q: What's the best way to determine the census tract number for a property location in LandView® III?
A: Because the Census demographic layer boundaries are generalized (see Generalized boundaries under LandView III "Help" for further details) they are unsuitable for visually determining the governmental or statistical area for a point near the census tract or block group boundary. To accurately determine census tracts and block group codes, you must use the "Describe Census Area" function under "LandView databases" in the MARPLOT Sharing Menu
To locate a street address or an intersection (for areas lacking address information) on the map, you will need one of the local discs (Discs 1- 10) which contains the Census 1995 TIGER/Line roads and major roads layers. (Note - The following example uses Prince William county, VA because it is part of the LandView user tutorial that is included on all LandView III discs.)
Let's suppose that you are trying to determine the census tract and block group for the following address in Prince William county, VA:
7948 Lomond Court
Manassas, VA 20109
Step 1. Creating the MARPLOT map view - Before the MARPLOT mapping program can search for the street or street address, you need to bring up the local map view. This is most easily accomplished by selecting the appropriate geographic summary level like county, place or minor civil division from within the LandView program and then clicking the "Show on Map" button. If you do not know the county in which the address is located, you can position the map to the 5 digit ZIP code by selecting the "Find ZIP Code on the Map" option under the LandView "MAP" menu.
Step 2. Setting up the Street Search - To search for your address in MARPLOT, bring up the search criteria dialog box by selecting "Search" from the "LIST" menu. The Search Criteria dialog box, which comes up when you select the Search menu item, is used to find objects according to various criteria you specify. Click on the pop-up box under the label "Search for objects: " and select "with names that start with ...". After "Layer(s) to search: " choose "Individual Layer..." in the first pop-up box and "Roads" in the second pop-up box. After "Map(s) to search:" choose "Maps in View" and leave the final pop-up box set to "replace previous collection." Then type "Lomond" in the text box next to the "with names that start with" box. Click the Search button.
Step 3. Identifying the Street Address- MARPLOT performs the search and puts all of the objects that match the specified criteria into the "Search Collection". In this case, you found 5 objects in the collection based on the entry "Lomond." There is only one street named "Lomond Ct." in the search collection. Click once on "Lomond Ct." to highlight it. Clicking on the "Addresses" button, you find an address range of "7900-7999". You now click on the "Show on Map & Zoom" button to see the section of the map containing "Lomond Ct." For streets lacking address ranges, you can use the "Intersections" button to position on the map.
Step 4. Mapping the Street Segment Containing the Address Range - MARPLOT creates a zoomed in map view of "Lomond Ct." with the street highlighted with a series of red boxes as shown below. Lomond Court joins Lomond Drive which forms part of the census tract boundary between census tracts 9016.01 (shaded in blue) and 9017.98 (shaded in yellow). Note that the MARPLOT census tract labels are composed of the FIPS state, FIPS county and census tract codes.
Step 5. Determining the Census Areas at Current Map Pointer - As noted in the above illustration, the generalized tract boundary does not precisely follow Lomond Drive (the tract boundary). Therefore, you must use the "Describe Census Areas " item which is shown under the "LandView databases" in the MARPLOT "SHARING" menu to accurately determine the census tract and block group. Doing so produces the following screen that identifies the census area for the highlighted section of the street.
Step 6. Determining the Street Side for an Address Range - You can even determine which side of street contains the address range by selecting "SEGMENT SETTINGS" under the MARPLOT "OBJECTS" menu. Doing so invokes the following segment settings screen.
This feature is particularly useful for those situations where the street segment forms a census tract or block group boundary. After determining the side of street the address is on, we recommend that you move the focus point from highlighting the street to the appropriate side and then repeat Step 5.
Note: The field "TIGER line ID:"contains a unique 10 digit code that identifies the TIGER/Line record that was used to build the segment. Please refer to this identification number in reporting any anomalies regarding TIGER/Line street information.
