The Southside Planning District was recently granted funding from VITA to perform a district-wide, comprehensive update of our address points and road centerline GIS data. This project will examine the data, make corrections where needed, compare address points to their geocoded positions on our road centerline data, and compare this data to telephone company data. The purpose is to increase public safety by making better data available to our three county 911 PSAPS. The updated GIS data will also be required for Next Generation 911 systems coming in the future.
This is a VITA Shared Services Grant, and will cover all three of our counties: Brunswick, Halifax, and Mecklenburg. Halifax County is the host applicant, and SPDC will undertake the tasks for this project.
Phase 1 is the most time-consuming part of this project. Using a grid-by-grid approach, staff will take a detailed look at address point data and road centerline data in a small area. Address points will be examined for the following errors, and corrected:
- Does the address point fall inside of the building footprint that should encompass it?
- If not, it's moved to the appropriate location
- Is the address number accurate (compared to other data, mostly tax parcel information)
- Are groups of addresses shifted from their appropriate locations? (likely a paper-to-digital conversion error)
- Does the address number correlate well to its location on the road centerline, using geocoding
- We use our geocoding tools, and recent analysis by VITA to determine if address ranges need adjustment
- Are there duplicate addresses on this particular road?
- Does the address correspond to a building that is no longer there? (if so, it will be deleted)
- Are other parts of the address information incorrect:
- Is the road name correct?
- Is there a community name in the attribute information?
- Other errors?
- As we examine and update addresses, they are tagged with date and status updates.
Road centerlines will be examined for these types of errors:
- Are the major attribute data elements correct?
- Road name, classification, dual carriageway status, one way status, etc
- Is the name parsed out into the correct attributes, such as Prefix, Suffix, etc
- Are these address range attributes populated:
- Left and Right To/From fields
- Overall to/from fields
- Evenside (if not on right side)
- If analysis shows that addresses are not geocoding properly, we will re-range the road centerline to better fit the existing address numbers
The progress of Phase 1 can be tracked on this map:
Phase 2 will involve comparing address and road centerline data to the MSAG and ALI databases used by the telephone companies to provide 911 service to the area. Changes needed in those databases will be supplied to the local telephone provider.
Phase 3 is QA/QC and will involve testing for accuracy and using VITA's GIS data analysis to ensure that improvement has taken place.