Economic optimisation of road network safety investment programmes

Byaruhanga, Bic Chris ORCID: 0000-0001-9050-0663 (2023). Economic optimisation of road network safety investment programmes. University of Birmingham. Ph.D.

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Abstract

The World Health Organisation (WHO) estimates indicate that 1.35 million people die annually because of road traffic crashes. Socio-economic costs associated with this major global public health concern may be 1-5% of Gross Domestic Product (GDP) in most countries. To reduce this global burden, the United Nations (UN), Bloomberg Initiative for Global Road Safety (BIGRS) and Global Road Safety Facility (GRSF) programmes and initiatives aim at reducing these road traffic crashes. Despite the above concerted effort, road traffic crashes remain a growing public health concern worldwide. The safe system approach endorsed by Organisation for Economic Co-operation and Development (OECD) represents a paradigm shift in road safety management in which support for infrastructure safety investment is one of the priorities. Economic analysis is a critical component of infrastructure safety investment that provides the basis for prioritising and selecting road safety projects or countermeasures. The economic principles and concepts are usually simplified and embedded in road safety investment appraisal models.

To date, no study has conducted a critical exploration, evaluation and synthesis of these models. As a first step, this Thesis systematically reviewed the available models with the aim to integrate and document the current knowledge and its gaps. Cost benefit analysis (CBA) may underestimate economic benefits depending on the approach used, thus the need for sound economic analysis. In practice, crash and casualty-based approaches are used in economic analysis of road safety infrastructure countermeasures most probably without due consideration of the impact of either approach. This research attempts to clarify the economic benefits of these two approaches and their impact in the selection of infrastructure countermeasures through a quantitative study. Financial constraints in road network safety investment programmes and the inefficiency of tools like CBA have led to the growth of economic optimisation tools. Unfortunately, none of the previous developed budget optimisation models considers the life span of countermeasures and their funding. Certainly, without categorising measures, it is possible to preclude the selection of several countermeasures that may enhance a programme’s effectiveness within the budget constraints. Therefore, this research develops the concept of countermeasure prioritisation by considering an optimisation method that takes into account both their life span and the available funding to implement an infrastructure improvement programme. To illustrate the application of the proposed model developed using the LINGO software, two case studies from the Netherlands and Indonesia are applied.

According to the results of the systematic review, there are no standardised methods for conducting economic appraisal and the performance of road safety countermeasures. The results of the comparative quantitative study demonstrated that a crash-based approach is more comprehensive and results in a wider range of countermeasures selected for implementation. Furthermore, the results from the newly developed model show that this new approach seems to enhance the prioritisation process. Capital and maintenance countermeasures are equally important. Their importance increases with increasing budget constraints. However, capital and maintenance countermeasures are more important in developing and developed countries respectively. Therefore, this research recommends adoption of a crash-based approach and life span categorisation of countermeasures to improve business cases and effectiveness of road network safety investment programmes.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

Supervisor(s):