Michelle M. Groce
The Solid Waste Services Department of Charlotte, North Carolina, includes three operational divisions: Collections Services, Special Services, and Community Improvement. GIS has become a critical tool in service delivery for all three divisions for developing and maintaining a wide variety of routes, managing requests for service, performing trend analysis and strategic planning, and also for parcel identification and ownership for the enforcement of the city litter code ordinance.
As of May 2002, the Collection Services division provides 560 weekly routed services to 173,730 locations in Charlotte: garbage, recycling, and yard waste. The Special Services division maintains routes for street sweeping and seasonal leaf collection. Service locations are maintained in a custom City application called Emerald, which uses an Oracle database engine. Currently, the locations are periodically exported and geocoded in preparation for routing, using Esri ArcView and Routesmart Technologies routing application. Historically, routes maps have been maintained as polygons in ArcView shapefiles, accessible for printing through the use of a Visual Basic application using Esri MapObjects. Route map maintenance is in migration to a parcel-based platform, using Esri ArcIMS, Microsoft SQL Server and Esri SDE.
Key elements for successful route maintenance for SWS include an accurate street centerline map as well as service locations that can be successfully geocoded to the centerline file. The street centerline file in Charlotte is maintained jointly by city and county agencies and includes data mandatory for routing: unique ids for each street segment and address ranges per segment (lower left, upper left, lower right, upper right.) Routing-specific information is created and related to the centerline file by SWS staff: speed limits, elevation, no left turn, etc. Service locations for Charlotte SWS are stored in Emerald, verified and maintained by SWS staff, and include service-specific attributes: dwelling description (single family house, mobile home, condo, etc) and service type (automated, rear-loader, handicapped.) The dwelling description is important for field identification; service types are used in routing.
In route creation or modification, which is a common occurrence in Charlotte SWS, calibration of route information using historical route data and tonnage is an important first step. Drivers complete daily sheets that track travel time, time on route, and time at the landfill. In the Routesmart routing application, demand (tonnage) and service time per location are the variables used to adjust route time to match actual average route time. Service time increases incrementally from automated, rear-loader, and handicapped locations; capturing the correct service requirements is vital to the accuracy and usefulness of automated routes.
Bulky item collection is a service available on an on-demand basis. Residents contact Solid Waste Services by telephone, fax, email, or web form with the item information and are scheduled for service on their regular collection days. Bulky item collection is offered to all service locations identified in the SWS database. Each day at 1:00 pm, no more pickups are scheduled for the following service day. Operations staff uses the VB MapObjects to query Emerald and generate maps for all scheduled pickups: approximately 17 daily routes for 1000+ items.
The City of Charlotte is divided into four service zones, each funded separately by a five-year contract awarded through a process in which Charlotte SWS must compile and submit a competitive bid along with private sector vendors. During the bid creation process, routing is a crucial tool used for load balancing, resource planning, and predictive models. What-if scenarios using alternative landfills, equipment types, equipment counts, or transfers stations are essential tools for production of a competitive, realistic bid. Operations staff plays an active role in assessing route feasibility and alternative solutions. Routes are generated as previously described; emphasis in the bid generation process is on the higher-level analysis of service day boundaries and equipment requirements, not specific travel paths.
The Community Improvement Division of Solid Waste Services is responsible for enforcing the Health and Sanitation ordinance of the Charlotte City Code. Inspectors issue violations for excessive weeds and grass, junk cars, graffiti, and other unsightly or unsafe property conditions. Each inspector has a service area in he or she works to identify and cite problem locations, but the inspectors also take citizen requests that come to SWS and are logged in Emerald. In either case, once a location is identified as a problem, the inspector has to research ownership in order to issue a violation. In the past, inspectors had to go the tax office and search through physical documents to confirm ownership. Now, inspectors save many hours by using the NC GIS: Online Real Estate System developed by Mecklenburg County available on the web to identify property owners and print property dimension maps for contractors who perform remediation.
Current challenges with using GIS in Charlotte SWS include some problems that will hopefully be resolved with moving from ArcView shapefiles to an ArcIMS/SDE platform with a more powerful database engine: staying current with a dynamic street file, reconciliation of different street names from one system (street file) to another (Emerald). Resolving unmatched service locations and generating routes for services with varying participation rates (recycling and yard waste) are problems currently being addressed through process analysis. Clearly, Charlotte Solid Waste Services relies heavily on the use of GIS to do business in creative and cost-effective ways.