Abstract

"Canada's municipal infrastructure is at risk." This was the key finding of Canada’s first municipal infrastructure report card. Given the current state of risk for Canadian infrastructure, municipalities face challenging decisions for planning the integrated repair/renewal of road, water and sewer networks. Decision-making surrounding the assets in these networks requires data collection, analysis, the identification of decision variables and undertaking optimized decision-making processes. Currently there is a lack of tools available to simplify the decision making process for stakeholders.
The research objective is to establish a methodology and framework that facilitates decision-making processes used during corridor rehabilitation project planning. The proposed framework consists of three main models: (1) Risk assessment, (2) Performance evaluation and (3) Integrated decision support system (IDSS).
The risk model was developed using a mixed Delphi-Analytical Hierarchy Process approach. The impacts of four main consequences of failure with eighteen sub factors were considered. Road, water and sewer networks indices were amalgamated and grouped into an overall integrated risk index using K-means Clustering technique. The performance model considers nine factors that represent the asset performance. These factors were mapped using fuzzy logic technique to a Customer Driven Performance Measure (CDPM) index. The IDSS framework allows the setting of priorities for integrated corridor rehabilitation and implementing optimization via Integer Programming. Finally, these models were applied in a prototype tool using Visual Basic built on Microsoft Access, Excel and GIS platforms. A series of workshop interviews were conducted with various municipalities to collect the necessary information. Data provided by the City of Guelph was used in a case study in order to demonstrate the model features.
Results show that Pipe/road size and accessibility factors had the highest impact on the integrated risk index. The road roughness rating and watermain breaks results show the highest impact on the CDPM index. Optimization outcomes demonstrated that corridor rehabilitation alternatives resulted in a ‘maximum risk reduced per dollar spent’. The developed models can be used by researchers and practitioners (municipal engineers and consultants) in order to prioritize corridor rehabilitation projects thereby easing the challenge faced by stakeholders regarding the future of municipal infrastructure.