The Effects of Transport Urban Renewal: A Study of Road-Rail Level Crossings in Melbourne, Australia

Abstract

ABSTRACT Transport infrastructure plays a vital role in shaping and structuring urban economic, environmental, and social activities by enabling access to destinations. However, it can also pose a significant barrier for communities. Despite numerous studies documented the enabler effects of transport infrastructures, little research focuses on identifying their barrier effects (or community severance). Most of these studies, however, focus on a particular type of barrier effect (direct, indirect, or wider) using cross-sectional data, and as a result, they lack to provide causal evidence of barrier effects in a more systematic way. Studies have hypothesized that direct, indirect and wider barrier effects occur in a sequential manner. Rarely studies examined this sequential flow on barrier effects (from direct to indirect to wider) and how they vary according to the design of transport infrastructure. This study aims to address these gaps in the literature using the road-rail level crossing removal project (LXRP) in Melbourne as a case study. In particular, the study questions and objectives are: Research Question 1: To what extent does the renewal of level crossings reduce community severance directly, indirectly, and catalytically? Research Objective 1: Assess the direct barrier removal effects of rail crossing upgrade Research Objective 2: Assess the indirect barrier removal effects of rail crossing upgrade Research Objective 3: Assess the wider/catalytic barrier removal effects of rail crossing upgrade Research Question 2: What is the level of (in)consistency between objective and subjective measures of barrier removal effects caused by the renewal of level crossings? Research Objective 4: Assess the consistency of the objective and subjective measures of the wider barrier removal effects. To answer the research questions, a combination of quantitative and qualitative data collection methods was employed. Qualitative data was used to understand the perceived barrier removal effects of LXRPs from the perspective of residents, whereas quantitative data complemented the qualitative data to objectively measure the wider barrier removal effects of LXRPs. A quasi-panel design was utilized in this study to assess the impact of infrastructure upgrades on residents' perceptions of their urban environment. An online questionnaire survey was designed to collect qualitative data from 776 residents living around 13 LXRP sites (cases) and 13 control sites. The questionnaire captured residents' perceptions of changes in the patterns of walking and cycling, travel time, and social life within their neighborhoods, respectively representing direct, indirect, and wider barrier removal v effects. Kruskal-Wallis and Mann-Whitney U tests were used to understand if the reported changes were significantly different between the case and control sites. Quantitative data collection involved the extraction of land use data from satellite images in the case and control sites in 2015 (pre-LXRP) and 2020 (post-LXRP). The case-control study design ensured that the observed changes in land use patterns in the LXRP sites were not due to chance (e.g. external effects). A difference-in-difference method was employed to robustly infer about the causal impacts of LXRPs on land use patterns. Furthermore, the gathering of both qualitative and quantitative data enabled the study to evaluate the degree of consistency between the two measures. This evaluation was conducted using the %agreement analysis to assess the level of agreement between these two types of measures. The survey data indicate that the removal of level crossing barriers resulted in: a) an enjoyment of walking and cycling in the communities (direct effects); b) a reduction in cycling time to workplaces, shops and restaurants, and schools (indirect effects); and c) an increase in open spaces and commercial use, and a decrease in residential areas (wider effects). Note, however, that some of the positive effects were found only when the new infrastructure was built above the ground suggesting the significant effects of infrastructure design on barrier removal effects. The %agreement analysis results, however show that while there is a considerable agreement between the objective and subjective measures in the perception of changes in shops and restaurants, parking lots and public buildings, noticeable inconsistencies exist in the measurement of houses and apartments, vacant lots and industrial buildings. This thesis, for the first time, provides causal evidence of barrier removal effects of transport infrastructure and how these can be observed in a sequential order from direct to indirect to wider. The findings are encouraging for transport authorities aiming to reduce barrier effects for communities. It also provides evidence of the effective ways of reducing the barrier effects through the design of infrastructure (above the ground vs. underground). However, the discrepancy between the objective and subjective measures suggests that residents are unaware of the positive impacts that LXRPs are making on the communities. This can be achieved, for example, through communication strategies.