In the predawn hours, crews from the Los Angeles Bureau of Sanitation assemble in staging areas for assignment details prior to their daily deployment for the removal and disposal of recyclables and waste throughout the city's vast 450-square-mile service area. In addition to its regularly scheduled pickups, the bureau's Solid Resources Collection Division (SRCD) collects bulky items, white goods (including refrigerators and washing machines) and dead animals. These services are scheduled by appointment for the 60 special-collection drivers who field more than 55,000 pickup requests each month.
Not so long ago, SRCD crews would meet with their supervisors each morning to map out the day's schedule for this service using traditional map books and the drivers' familiarity with the area to determine the assigned routes. These meetings lasted about 30 minutes, which significantly reduced time spent on the road.
“While this manual routing method worked for us in the past, there were increasing demands on our services, and we simply needed to find a more efficient method for route planning,” says Sal Aguilar, geographic information systems (GIS) manager at SRCD.
After evaluating various systems, the department decided to implement a GIS that includes ESRI's ArcLogistics for point-to-point routing; RouteSmart for continuous routing applications; and ArcGIS Desktop and ArcGIS Server for mapping, analysis and geodatabase management.
Now, when requests for bulk item collections and container service are received, the details are input into a central database and downloaded to PCs at the various dispatch centers. There, supervisors review the pickup requests and generate route maps before each shift. The maps and any last-minute instructions or route changes are then exported to the crews' personal digital assistants (PDAs), which they pick up in the dispatch office before beginning their daily assignments.
Observes Aguilar, “With the automation and optimization of our routing procedures, we have realized a significant cost/time benefit as well as the capability to provide better service to our customers.”
While route planning is the SRCD's primary use of GIS, Aguilar continues to push the technology to develop new efficiencies in the department. For example, geocoding (determining the latitude and longitude coordinates) of the city's 1.5 million residential and commercial addresses was time-consuming; however, it has provided major benefits to the department in other GIS applications.
“The ability to develop a mailing list based on an irregularly shaped boundary is very useful to us,” says Aguilar. “We can do this in the database, of course, but it is a much more complex process.”
Using the software, Aguilar is able to draw a boundary around a certain geographic area, then export a tabulated list of customers' addresses in that area. “This is really helpful, for example, when we have our various pickup sweeps of bulky items,” he says. “This service is important to our customers, and we want to make sure that we get the word out so they can make use of the special pickup.”
Aguilar also is using GIS to implement operational route-based analyses on all (more than 2,500) regular routes to make sure that trash pickup is balanced throughout the entire network. “We look at the operational parameters of the routes and display them spatially to analyze the relationships between them and determine where improvements can be made,” Aguilar says.
Vehicle routing is a dynamic process with parameters that are in constant flux. There is always the potential for unplanned roadway construction, temporary speed limit changes, accidents, congestion and so on. Because of this, says Aguilar, the automatic routing solutions provided by the GIS aren't always perfect, “but it does allow us to systematically approach how we assign work.”
The department also plans to install on-board computers in each collection truck for continuous routes. The computers will automatically record the number of stops made and the number of containers picked up at each stop via a radio frequency (RF) unit. This data will be collected continuously via a cellular modem for postprocessing, so drivers don't have to worry about collecting the data themselves. This information will be used to help optimize the routes and make sure that each area is adequately serviced with no missed collections. It also will enable daily container inventory tracking.
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Jim Baumann writes about international GIS-related topics for ESRI. He has written articles on various aspects of the computer graphics industry and information technology for more than 20 years.