Collection and Transportation of Wastes: The Application of A Systematic Collection Route Design Process for Curbside Recycling Larry W. Minor and Lowell K. Shaw The UNC Institute for Transportation Research and Education A Paper Presented at Land-of-Sky Regional Council Waste-to-Resources: LocaljRegional Solid Waste Alternatives June 9-10, 1988 Asheville, North Carolina Introduction A number of factors affect the collection and transportation of wastes. Specifically, this paper will focus on the application of a systematic collection route design process for curbside recycling. The main purpose of this systematic process is to promote efficient collection of recyclable materials. systematic process for collection route design for A curbside recycling should, at a minimum, include the following: 1) route sizing; 2) development of an overall routing plan; and 3) provisions for the implementation of the collection route design. Route Sizing Route sizing is an important component of a systematic collection route design process and is an important factor in efficient curbside collection of recyclable materials. Route sizing is the process of determining the following: 1) number of households to be collected and 2) number of collection districts or routes needed. These two variables will be key inputs in the route sizing process. The process of determining the number of households to be collected should include the following: 1) determining the entire number of households to be collected (i.e., the entire service area) and 2) calculating the average number of households per route (i.e., crew workload analysis). The main results of the route sizing process are the determination of the number of crews and collection vehicles required to adequately cover the proposed collection service area. Collection costs can vary significantly depending upon the 1
accuracy of this particular part of the collection route design process. As a preliminary step to route sizing, a curbside recycling survey should be conducted to determine roughly how many residents are expected to participate in the program. The survey should be a relevant sample for the community at large. When communities are considering a curbside collection service it would be advisable to implement a small-scale pilot program first. There are several advantages to doing this. First, collection route procedures can be tested to see if they meet anticipated program goals. Any unusual problems such as recyclable scavaging or poor container placement can be addressed early. Second, collection truck specifications may require alteration. By examining primary routing data listed above and the amount of recyclables collected, the number of trips required to the processing center can be determined. This in turn, will reveal whether larger collection trucks are necessary and whether they are adequately collecting materials for easy handling. The time required to collect recyclables is greatly influenced by whether they are pre-sorted. Also, the individual truck bins for each material may have to be modified if it is found that one material is prevalent. For instance, if glass bottles and aluminum cans make up the majority of the total quantity collected and they are put together in one bin, they may not meet manufacturers specifications for cleanliness or may increase processing times at the processing center. These issues can be dealt with at the pilot program stage. Finally, the pilot program will determine whether the curbside recycling effort is feasible on a larger scale. Developing A Routing Plan The next component of the systematic collection route design process for curbside recycling is development of an overall routing plan. This part of the process will include macrorouting, districting and micro-routing (see Figure 1). Macro-routing is the assignment of collection routes to processing sites. Macro-routing analyzes round-trip haul times for each route to the processing center (including queue or waiting time at the center). This type of situation would more likely exist in the larger, more populated urban areas. Districting is usually referred to as the determination of route boundaries and route balancing. This is the process by 2
DI STRl CTI NG: DETERMINATION OF ROUTE BOUNDARIES, ROUTE BALANCING. 0 Wednesday t=i Thursday [- Truck #1 M ACRO-R 0 UTI NG: ASSIGNMENT OF COLLECTION ROUTES TO PROCESSING 8, DISPOSAL SIT $. 0 To landfill 00 To incinerator SOURCE: Heuristic Routing for Solid Waste Collection Vehicles. (EPA, 1974)., -. -.. -....... -. MI C.R 0-R 0 UTI N G: PATH OF COLLECTION VEHICLE ON THE ROUTE. Figure 1. Types of routing: (1) macro-routing is assigning collection routes to processing and dispoal sites; (2) districting is determining route boundaries and mute babncing; (3) micro-routing is determining the path of collection vehicles. on the route. The heuristic approach described in this report applies to micro-mu ting.
. which a fair day's work for crews is determined (i.e., crew workload analysis) and the entire service area is divided into balanced routes (usually by time) so that all crews have relatively equal workloads. Districting can be done by analyzing the time components of a work day such as the travel from the garage to the route, collection of the route, travel from the route to the processing center, lunch breaks, vehicle breakdowns and travel from the route to the garage. The housing density along the route and the amount of recyclables collected should also be taken into account. Several factors to be considered when laying out boundaries include; results of crew workload analysis which determines the average number of pick-ups provided per crew, the density of residential development such as services provided per square mile and average collection times per each service, consideration of natural barriers to collection such as rivers, arterial streets/highways etc., and the possibility of future residential development. Micro-routing is the part of the process which determines the path of the collection vehicle on the route, including beginning and ending points. A specific product of micro-routing is vehicle path routing plans, which are usually draw on maps (see Figure 2). Micro-routing involves the application of heuristic (i.e., systematic) methods of vehicle routing to minimize the noncollection distance and delay times for each vehicle. Several rules of thumb are considered, such as the following: routes should be compact, continuous, initiated close to the collection vehicle garage (where possible), avoid heavily traveled streets during rush hour and follow determined paths for one or two-sided curb collection. There will be occasions whereby the existing collection route design (i.e., route boundaries and vehicle path routing) should be redesigned. One such occasion would be where the number of households participating in the curbside program may change. Other occasions may be where collection crew workloads may need to be re-adjusted due to changes in volumes collected, cost reduction efforts by curbside authorities or energy conservation efforts. Finally, 'If ine-tuning" the curbside collection system may lead to some redesign of specific areas. Information required to perform vehicle path analysis includes; traffic controls, dead-end streets, truck prohibitions, traffic volumes and area topography. Efficient path routing will 3
INSTITUTE FOR TRANSPORTATION RESEARCH AND EDUCATION P. 0. Box 12557. Research Trranolt? Park. N.C 27709-1' JY" AL=--.- *, \*, K Legend Figure 2: Sample Vehicle Routing Map
4 " result in fuel savings, collection time savings, reduction of vehicle wear and tear and reduction of "non-productivel' crew time. Implementation of Collection Route Design The final component of a systematic collection route design process is provisions for the implementation of the collection route design. This is a continuous process which begins at the beginning of the collection route design process and continues with the implementation of routes. Two important aspects of the implementation component are as follow: 1) consideration of the costs of implementation and 2) developing and establishing procedures for implementing a new collection route design. Consideration of the costs of implementation should involve addressing the following issues and tasks : 1) performing '!dry runs" of newly-designed collection routes; 2) data collection, recording, analysis, monitoring and evaluation; 3) development of materials and resources for public information campaign; 4) financial incentives for collectors and other workers; 5) establishing procedures for handling of citizen and media inquiries; 6) risking and jeopardizing the operation's reputation of good service. Some suggested procedures for implementing a new collection routing design might include the following: 1) performing!'dry run" of new collection routes; 2) develop lines of communication with drivers/crews and provide incentives to ' comply with collection system changes; 3) conduct a thorough public information campaign; 4) implement a data collection, analysis, monitoring and evaluation system. Management should have crews conduct "dry runs" to accomplish the following: 1) to verify that the proposed new routes are workable in practice; 2) to facilitate the handling of crew concerns and complaints related to the running of routes; and 3) to modify routes when needed. The objective Gf the data collection, analysis, monitoring and evaluation system should be to collect, analysis, monitor and evaluate detailed performance data on the following: 1) transportation costs (fixed and variable); 2) recyclable materials quantities (weight and volume); and 3) man-hours and mileage for collection, hauling, disposal at the processing center and travel to and from the route to the collection vehicle garage. 4
t Conclusion The application of a systematic collection route design process is desirable to ensure the develop of an efficient curbside recycling program. The main components of a systematic collection route design process are as follow: 1) route sizing; 2) development of a routing plan; and 3) implementation of the collection route design. 5