Procedia Engineering 77 ( 2014 ) 20 – 27

1877-7058 © 2014 Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/).Selection and peer-review under responsibility of the Department of Urban and Infrastructure Engineering, NED University of Engineering and Technologydoi: 10.1016/j.proeng.2014.07.023

ScienceDirectAvailable online at www.sciencedirect.com

Fourth International Symposium on Infrastructure Engineering in Developing Countries, IEDC 2013

Solid waste collection routes optimization via GIS techniques in Ipoh city, Malaysia

Amirhossein Malakahmada,*, Putri Md Bakria, Munirah Radin Md Mokhtara,Noordiana Khalila

aCivil Engineering Department, Universiti Teknologi PETRONAS, Teronoh 31750, Malaysia

Abstract

Waste collection becomes more complex in developing countries in terms oflogistic, fuel and labor cost and air pollutantsemission. In this study, solid waste collection routes optimizationusing Geographical Information System (GIS-ArcView) was investigated. Five routes were selected in different area of Ipoh city for pilot study and the present routes wereoptimized to reduce the length of the routes and consequently the time taken to complete the collection. Results indicate up to22% length minimization in the routes. The collection duration was also reduced from 6934s to 4602 s. © 2014 The Authors. Published by Elsevier Ltd. Selection and peer-review under responsibility of the Department of Urban and Infrastructure Engineering, NED University of Engineering and Technology.

Keywords: Route minimization; urban area; Perak state; curbside collection

1. Introduction

Solid waste collection is a major sectionin the process of solid waste management (SWM) and it is estimated to consume up to two third of entire SWM budget. The functional element of collection includes not only the gathering of solid wastes and recyclable materials, but also the transport of these materials, after collection, to the location where the collection vehicle is emptied [1]. This location may be amaterials-processing facility, a transfer

* Corresponding author. Tel.: +6-05-368-7349; fax: +6-05-3656716. E-mail address:amirhossein@petronas.com.my

© 2014 Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/).Peer-review under responsibility of the Accounting Research Institute, Universiti Teknologi MARA.

21 Amirhossein Malakahmad et al. / Procedia Engineering 77 ( 2014 ) 20 – 27

station, or a landfill disposal site. Collection of solid waste in an urban area is difficult and complex because the generation of wastes takes place in every house, apartment, commercial and individual facility as well as in the streets, parks, and even vacant areas [2]. Therefore, in any waste collection operation, it is important to look into; types of waste collection services/systems, type of equipment to be used and associated labor requirements and collection routes.

Once equipment and labor requirements have been determined, collection routes must be laid out so that both collectors and equipment are used effectively. There is no universal set of rules that can be applied to all situations [1]. Therefore, optimization of solid waste collection routes in urban area is important where significant amount of the time is spent loading and unloading as well as driving. Optimizing of collection services is still depending on the knowledge of local conditions such as one-way streets and road construction by the collection teams.Therefore, many researches have been carried out globally to overcome the municipal solid waste collection in localized scales as summarized in Table 1.

Review of literatures show the popularity of Geographical Information System (GIS) for the route optimization studies. GIS is suitable tool for these kinds of study as it is capable to store, retrieve and analyze a large amount of data as well as outputs visualizationin a resoanable duration [8].Fundamentally, GIS provides network-based spatial analysis and application of ArcGIS Network Analyst, make the user able to dynamically model realistic network conditions, including turns and height restrictions, one-way streets, speed limits, and variable travel speeds based on the local traffic [9].

1.1. Study area

Part of Ipoh City including five areas namely Buntong, North Ipoh, Kg Baru, Falim and Menglembu were selected as pilot scale study. Ipoh city is located in the state of Perak in peninsular Malaysia and it is 200 km north of Kuala Lumpur. The city is under the administration of Ipoh City Council (MBI).According to 2007 statistics report, the population of the city is 710798 [10]. Ipoh has a typical of a rainforest climate, with temperatures range from 20.7 °C to 30.6 °C throughout the year. The average rainfall in Ipoh varies from 417.0 to 1029.0 mm/month [11].

Table 1. Summary of route optimization studiesLocation Modifications by ArcGIS Results Reference

Leganes, Spain

Designed routes for the "bin to bin" (BTB) collection of paper and cardboard waste (PCB) from small businesses, as well as with the new location and calculation of the number of containers needed in the streets for both commercial and non-commercial uses due to large amount of PCB deposited in them.

Reduction of waste in bin due to frequent service collection for shops.

[3]

Athens, Greece

Provide efficient routing for trucks to collect large wasted items.

An optimum shortest route was determined with minimum cost taken into account.

[4]

Trabzon City, Turkey

Propose optimized routes to reduce the emissions from trucks exhaust during solid waste collection process.

The travel time decreased by considerable percentages and exhaust gas emission was reduced and thus operational cost was also reduced.

[5]

Republic of Cape Verde, Africa

Calculate the vehicle routing in terms of fuel consumption and time travel for solid waste collection.

16% fuel saving and 29% distance minimization were obtained.

[6]

Churrianade la Vega, Spain

Determine an optimal model for improving municipal collection in the study area.

Reduction of the solid waste collection route lengthand travel time.

[7]

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1.2. Solid waste management in Ipoh city

MBI as a local authority administrates Ipoh city public health and sanitation, waste removal and management, town planning, environmental protection and building control, social and economic development and general maintenance functions of urban infrastructure. Due to geographical area and population, Ipoh city is divided into 22 zones for effective solid waste collection. The collection is held every alternate day for majority of the zones. It includes collection of residential area waste as well as bulky waste produced from industrial area, shopping complex and shops. Segregation of the waste is not practiced by producers and separate collection of different type of waste is not performed by the city council. The collection method is curbside collection and common containers are used so that the crews empty the containers into the collection vehicles prior travel to disposal site. A typical crew during solid waste collection consists of a driver and three collectors. The collected wastes are sent to Bercham dumping site. These incoming non separated wastes have made theBercham dumpsite almost full.

2. Objective

The bulk of solid waste generated in the city is a complex mixture of different materialsincluding both biodegradable and recyclable waste with very different properties and potential for reuse. The aim of this study is to minimize the current routes distance and time which will resulted in availability of existing equipment and labour to perform separate collection of recyclable waste in the city.

3. Methodology

The method used was deliberated based on (1) territorial analysis, (2) GIS analysis, and (3) service design. The details of each step are explained in sections below:

3.1. Territorial analysis

This analysis was based on the identification of the needs and/or restrictions in the collection service. Five routes in the areas of Buntong, Ipoh North, Kg Baru, Falim and Menglembu were selected for the pilot study. Initially the selected routes were inspected according to topography, condition of the roads and other restrictions in the collection procedures. The selected routes are in the zones, which are nearer to the Bercham dump site compared to other zones. To process and analyse information that was the basis for the proposed methodology the following were provided according to Alvarez et al. [3]:

Street Plan in digital format (scale 1:6000), Orthophotos Community of Ipoh (scale 1:1500), GPS; to locate the stop points (which in turn were placed with name and street number).

In order to efficiently manage the solid waste collection system, detailed spatial information is needed. These data involved the geographical background of the study area and the procedure of the waste collection process. The data including location of the trucks, waste generation rate, type of waste bins, the road network and related traffic were obtained from MBI. Base map of Ipoh was obtained from department of survey and mapping Malaysia (JUPEM). Satellite images of Ipoh City were captured from the Google Earth.

3.2. GIS analysis

The use of the GIS allows the user to create, arrange, treat and analyse the geographical information, organized by means of graphic and alphanumeric data [12]. The GIS-ArcView were used which enables the users to have a

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geographical reference of entire points on the digital street map.To analyze the information through ArcView the order tracked in the study was the following:

3.2.1. Data processing

Initially, the data in AutoCAD(.dxf) were converted to shapefile (.shp) format using Mapinfo Professional (Fig. 1). All the layers such as road, drainage, elevation and contour layers were considered during the conversion. Then, the projected coordinate were used to standardize coordination system. The coordinate system is a reference tool used to represent the locations of geographic features, imagery, and observations, such as Global Positioning System (GPS) locations, within a common geographic framework [9].

3.2.2. Identification of the route

The municipal solid waste trucks routes were identified by comparing the images of the Google Earth and drawing from AutoCAD. All required data for processing purposes such as length and name of the roads were inserted into the attribute table. As illustrated in Fig. 1, georeferencing steps were conducted by overlapping of the Google Earth images and road layers to ensure the roads’ name are identified similar.

Fig.1. (a) Ipoh city based map, (b,c) identifying the layers in the map, (d) geodatabase map (e) areas of study in Network Analyst

a b c

d e

24 Amirhossein Malakahmad et al. / Procedia Engineering 77 ( 2014 ) 20 – 27

3.2.3. Identification of the layers

In the given drawing, there were many layers such as pipeline, contour, road and housing layers. With referencing with the Google Earth Image and Ipoh Map, user can identify the road layers needed for data analysis. Finally, non-spatial data such as road name and length of each road were added.

3.2.4. Creating network database

A Network Dataset was created from the feature sources that participated in the network. It incorporates an advanced connectivity model that can represent complex scenarios, such as multimodal transportation networks. It also possesses a rich network attribute model that helps model impedances, restrictions, and hierarchy for the network.

3.2.5. Creating network database

Arc-GIS-NA is an extension that provides network-based spatial analysis including routing, travel directions, closest facility and service area analysis. The NA is able to find efficient travel routes for the trucks during solid waste collection.In order to solve the route optimization, distance criteria and collection time by the truck (regardless to time spent in traffic) were considered and generated. By considering speed formula (v = d/ t)duration taken for each truck travelled throughout solid waste collection was obtained. The final output was an optimal solution in terms of distance criteria.After setting the stop points, the optimized routes for solid waste collection were produced. The stop-points were numbered automatically by Network Analyst in the order that they were visited.

3.3. Service design (definition of the routes)

Best possible routes for solid waste collection were identified based on the information obtained with the help of the GIS regarding the possible routes, and having taken into account the restrictions to the road conditions and topography. The routes were chosen in a way that the resources used for the collection,the length of the route and the time taken to complete the collection is minimized [13].

4. Results and discussion

4.1. Distance between collection points

Five routes were defined with the characteristics given in Table 2.Any reduction of distance between the collection points could be attractive as it reduces the collection time, cost and air pollution emission. There were more than one alternative to estimate the distance between two points. One efficient way of estimation is application of Euclidean space which is made with the Pythagoras theorem.

Table 2. Graphic design and length of the routes Area Route Present length (m) Optimized length (m)

Buntong Route 1 8390 6558

Ipoh North Route 2 7919 6764

Kg Baru Route 3 6918 5385

Falim Route 4 6351 5522

Menglembu Route 5 5170 4472

Total 34748 28701

25 Amirhossein Malakahmad et al. / Procedia Engineering 77 ( 2014 ) 20 – 27

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26 Amirhossein Malakahmad et al. / Procedia Engineering 77 ( 2014 ) 20 – 27

Table3. GIS-based designed routes information

Area Length (m) Duration (s) Number of stops Stops length (s) Total collection time (s)

Buntong 6558 472 17 510 982

Ipoh North 6764 487 15 450 937

Kg Baru 5385 388 20 600 988

Falim 5522 398 18 540 938

Menglembu 4472 322 21 630 952

Total 28701 2066 91 2730 4796

Truck speed and stop duration for each point were assumed to be 50 km/h and 30 s, respectively.

The proper frequency for the most satisfactory and economical service is governed by the amount of solid waste must be collected and by climate, cost, and public requests [14]. For the Route 1 in Buntong area and based on the measurement distance travelled for the truck (6558 m), the time taken for the solid waste collection was found to be 472 s. 17 stops have been designed in the route which resulted in 982 s total collection time in the Route 1.In same trend, the collection times for the Routs 2 to 5 in Ipoh North, Kg Baru, Falim and Mengelmbu were 937, 988, 938 and 952, respectively.According to the survey and information received from MBI, at present the time taken to collect the waste in the selected routes is near 2 hr (6934 s). This indicates the improvement of collection time in the new design compared to current situation. The total length of 2332 s was saved in new route design as the collection duration was reduced from 6934 s to 4602 s.

Based on the optimized conditions a master schedule for each collection route should be prepared for use by the engineering department, MBI and transportation subsidiaries companies. A schedule for each route, which includes the location and order of each pickup point to be serviced, should be prepared for the driver.

5. Conclusion

Collection of unseparated and separated solid waste in an urban area is complex as waste generation become more diffuse. Of the total amount of money spent for collection, transportation and disposal of solid waste, approximately 50 to 70 percent is spent on the collection phase. This fact is important as small percentage improvement in the collection operation can effect a significant saving in the overall cost. Therefore, interest in the analysis of solid waste collection systems arises to optimize the operation of existing systems and to develop data and advanced techniques to design and evaluate new systems for urban areas. GIS-ArcView application for route optimization in Ipoh city has shown reasonable improvement in length of the routes and travel time minimization. The results obtained from this pilot study are encouraging to expand the scope to cover entire city for optimization of the routes for solid waste collection. In addition to cost deduction, as more and more communities are moving toward mandatory recycling of materials, the route optimization will provide opportunities for separate collection of recyclable wasteusing same logistic and equipment. This will reduce the reliance of city councils to disposal sites and increase disposal sites operational life.

Acknowledgements

The authors thankfully acknowledge the financial support from The UniversitiTeknologi PETRONAS. In addition, the authors would like to thank MajlisBandaraya Ipoh (MBI) for their assistance and consultations during this project.

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