Improving the evaluation of transport infratructure projects

Abstract

Investment on transport infrastructure is a significant component in a country’s budget as it is identified as a key factor to facilitate the country’s development. At the same time demand for transportation is positively correlated with the development. With this increasing demand for transport infrastructure and funding available, proper evaluation is necessary to identify the most desirable alternative. Current appraisal practices at the early stages of projects fail to identify some important criterions and therefore, may ultimately end up not selecting the most appropriate project(s) which addresses contemporary concerns. Further it is necessary to assess whether the intended impacts were achieved through these projects, to continue with same kind of projects or to take necessary remedial actions. Therefore the objectives of this research were to identify cost effective methods and factors that should be considered in evaluating transport infrastructure projects both at pre-construction and post construction stages. Both academic and grey literature were reviewed to identify current practises; evaluation methodologies and impacts concerned. In depth interviews were held with experts in academia and industry to identify current practices and improvements needed. Study relieved that current practices focus only on direct and short term impacts and neglect wider impacts such as climate change impact, disaster resilience of communities and travel time reliability. Criterions that are needed to be considered to assess all the major impacts of transport infrastructure developments were selected based on literature and were broadly categorised into engineering, environmental, socioeconomic and transport based on the field of expertise of the evaluators of each impact. Linear additive model based on multi criteria analysis was selected for prefeasibility analysis as it helps to combine both quantitative and qualities impacts for the assessment and time, data and financial resources are limited to evaluate number of alternatives at this stage. Propensity score mating technique was selected for post construction evaluations, for the indicators which have suitable comparison groups. This was selected considering the fact that it takes considerable time to mobilise the impacts and transport interventions are not assigned randomly, but by considering social and geographic issues. However where no suitable comparison groups are available basic techniques such as pre post evaluation has to be used for post construction studies. The methodology of these two analysis techniques and ways to overcome the limitation are discussed in this thesis together with the indicators that should be selected to assess the impacts of transport projects.