Is Data Driving Your Fire Engine? Continued from page 35 For streets inside the district, Kent City Public Works maintains current streets for geocoding and, with minor enhancements, for emergency routing. For areas outside the district and throughout the South Valley, King County GIS provides regional streets. Valley Com is building a composite regional street dataset to support its dispatch and communications software implementation. County agencies provide their best street sets, which are being merged and standardized by a consultant. [For more information about network streets, download "It’s All about Streets" at www.esri.com/news/arcuser/1009/ networkstreets.html. To learn more about geocoding, check out "The Call Comes In" at www.esri.com/news/arcuser/0410/mp_geocoding. html.] The U.S. Census Bureau is updating its MAF/TIGER Database (MTDB) for the 2010 Census. These streets should be available after they have been finalized. TIGER 2009 streets can also be downloaded from www2.census.gov/cgi-bin/shapefiles2009/national-files. Since 2000, there have been many significant changes in TIGER streets. Positional alignment has been improved, and addressing is more complete. Although TIGER 2009 streets provide a good address geocoding reference, they do not include the network impedence values or appropriate directionality and crossing relationships needed for performing time-based analysis. While it is possible to build a network dataset from TIGER 2009 streets, it requires considerable effort and extensive local knowledge. Second Pick—Cadastral Next on my public safety wish list is county assessor parcel data. Parcels are constructed on the broader cadastral framework. County assessors typically use the Public Land Survey System (PLSS) to catalog and store parcel information. The availability, content, and spatial representation of assessor parcels varies considerably by jurisdiction. In the best case, attributes may include owner/occupant information, occupancy and use type, appraised and assessed valuation, and structural information. A robust, current assessor parcel dataset will support hazard and value mapping throughout a county. Obtaining this data can necessitate developing a relationship with the county assessor, which can take time and require the appropriate introductions. Since property values can quickly change in either direction, obtaining parcel data for several years may help. Assessor parcels are a key dataset when defining and structuring agency consolidations and developing or updating an agency’s revenue stream. Also, with sufficient single-family and multifamily residential information, the occupancy percentage and average family size can be estimated prior to the release of Census 2010 data. At Kent Fire/Fire District 37, assessor parcels provide information about new subdivisions and construction and changes in values and building occupancies. They define and support tax rates and are used for updating the Fire Benefit Charge. Parcel data can provide a reasonable estimate of street width and define candidate locations for proposed easements and new access. This data can also provide a framework for Fire Prevention Bureau staff as they perform inspections and update prefire plans. [Fire Prevention Bureaus provide public education, inspection and code enforcement, and detailed plan review.] Continued on page 38 36 ArcUser Summer 2010 www.esri.com