Geography Reference
In-Depth Information
system and provide greater efficiency. Rather than adopt the approach taken
by other studies and use VRP to only solve for the optimal routing strategy,
this research differs by proposing and modeling an alternate scenario that
utilizes several collection companies but remains efficient.
3.
D
ATA AND
M
ETHODS
This research design utilized the Vehicle Routing Problem (VRP) function
through ESRI's ArcGIS network analyst. The VRP is a type of network
analysis tool for routing a fleet of vehicles to service a set of orders with the
goal of minimizing some objective (e.g., operating cost), while satisfying
certain constraints. These constraints may include time windows, multiple
route capacities, travel duration constraints, route zone and route seed point
constraints, specialties constraints, and paired order constraints (ESRI GIS
Dictionary - http://support.esri.com/ en/knowledgebase/GISDictionary/term/
vehicle%20routing%20problem). Several studies have utilized VRP within
GIS for the purpose of assessing and designing improved waste collection
strategies (Jovicic et al., 2011; Bhambulkar2010; Kim et al., 2006 Sahoo et al.,
2005). Further, ArcGIS is readily available and is the most popular GIS
software package used within many state and local governments in the United
States. Local governments could apply this research design to their solid waste
collection strategies. VRP's user-interface within ArcGIS is user-friendly and
allows users to define a variety of inputs. Given these reasons and the
availability of data from the IRC, VRP within ArcGIS was chosen as the
methods to analyze waste collection in the City of Altoona.
For this research, the solid waste collection companies represent the fleet
of vehicles serving a set of orders comprised of residential households and
their solid waste. Constraints include time windows for companies to begin
and end collection, amount of solid waste per household, household collection
time, capacity of solid waste collection trucks, and typical road constraints
(speed limits, turn restrictions, traffic congestion) imposed by the road
network. The VRP provides output that includes driving directions, total
distance traveled, and total travel time.
Applying the VRP to solid waste collection in the City of Altoona
required several data and methodology considerations:
