Pedestrian level of service (PLOS) is a common method for assessing the quality of pedestrian facilities. This measure of walking conditions aids in developing street design and helps in evaluating and prioritising changes to footpaths when retrofitting and in designing new streets that promote sustainable transport. The development of pedestrian level of service (PLOS) measures has received considerable academic and practitioner attention, as transport agencies seek to encourage walking. Engineers and planners determine a link’s performance using measures codified as levels of service (LOS), which provide guidance on acceptable or desirable standards. A range of approaches is used in determining pedestrian levels of service (PLOS) incorporating a wide variety of factors and causing much debate as to what should or should not be used. Overall, the methodology to evaluate pedestrian level of service mainly involves determining the various factors which influence pedestrians in terms of perceived safety and comfort. This study had a set of inter-related objectives: a) to identify the various factors affecting PLOS on different pedestrian facilities using systematic methods; b) to select the appropriate factors for the Australian context that mainly influence the PLOS on footpaths in commercial areas; c) to examine the importance level of a wide range of factors affecting PLOS, and their relationship to each other; d) to develop two PLOS models, the first based on our new approach labeled ‘pedestrian disgruntlement’, and the second based on a satisfaction approach; and e) to develop a comprehensive PLOS model using an audit tool method to measure the overall PLOS value. Overall, the main aim of this research is to develop empirical and systematic PLOS measurements appropriate for the Australian context that reflect the perceived safety or comfort of pedestrians along footpath segments in commercial streets. A mixed-methods design is applied in the research in collecting and analysing data, including: i) a systematic quantitative literature review using the PRISMA technique examining more than 600 academic papers; ii) use of the Delphi technique for two rounds, including an online survey with 36 experts, after which 20 of the same experts participated in a follow-up ‘walkshop’; iii) an on–street pedestrian intercept questionnaire survey of 312 participants, gathering pedestrians' perceptions of the factors affecting PLOS; and iv) a point system method by allocating a four point scale for each item, starting from point zero representing the worst condition scenario (i.e., very unsafe/uncomfortable) to point 3, representing the best condition scenario (i.e., very safe/comfortable). The thesis results are presented as three published or submitted peer reviewed papers. In Chapter 4, the review surveyed PLOS models from the peer reviewed literature using a systematic quantitative literature review method based on the protocol developed by the Preferred Reporting Items for Systematic Review Recommendations (PRISMA). 58 of the 600 studies surveyed have been produced since the first study examining developing PLOS models was established in 1970. Later approaches use a much wider range of factors but there is very little consistency across the studies surveyed. Collectively these factors can be grouped into themes of comfort, safety and mobility. However, many of the factors being included have not been empirically studied and almost none of the tools in use have been tested for such matters as inter-rater reliability. In Chapter 5, a novel, robust method was developed for determining and measuring the factors that affect PLOS using a satisfaction approach, and a point system method for evaluating the full range of pedestrians’ opinions on footpaths in commercial streets. The overall PLOS score shows that the condition of measuring segments was better than moderate, which reflects pedestrians’ perceptions. In Chapter 6, the importance of a wide range of factors affecting PLOS was examined to explore how this relationship may differ for different ages and genders of pedestrians in different walking environments. The gap analysis approach was used. This has previously been used in measuring consumer perceptions of Quality of Service (QOS) in the service industries. A new method was developed to combine measures of pedestrian satisfaction with each factor and the perceived importance of that factor, creating a novel measure labelled ‘pedestrian disgruntlement’ to measure PLOS. The results demonstrate how the technique may be used to improve PLOS measurement and to allow comparison of service to satisfy particular population sub-groups. In Chapter 7 a reliable audit tool was developed which, depending on pedestrians’ perceptions, reflects their perceived safety or comfort along footpath segments in commercial areas. This tool was objectively used to collect and measure factors influencing pedestrian LOS. More specifically, this study might be considered a guideline for evaluating pedestrian level of services for such streets in Australian cities in a systemic, reliable and empirical manner. In this chapter, a guideline manual was also presented, providing specific information relating to the evaluation of pedestrian level of service (PLOS) on footpaths in commercial streets in Brisbane using the Pedestrian Level of Service Audit Tool (PLOSAT). This document provides instructions on how to organise and conduct an audit, the standards for pedestrian facilities and information about how to use the forms when conducting an onsite audit. A major methodological contribution of the study is in adopting a reliable, empirical and comprehensive method to collect data, measure factors affecting PLOS and evaluate PLOS for footpaths along commercial streets in Australian cities. The methodological approaches adopted include a systematic literature review, the Delphi process and a pedestrian intercept survey, plus inter-rater reliability testing. Few, if any, previous audit tools for real-world application have used such rigorous approaches in tool development. The applied contributions of the thesis are in developing an audit tool for PLOS that is systemic, reliable and empirical, developed with and for practitioners and end-users. The outcomes of the thesis could be used to improve pedestrian facilities using PLOS measurements to ensure that different pedestrian facilities are balanced with vehicular facilities and other land uses. The empirical and systematic PLOS measurements reflect the perceived safety or comfort of pedestrians along footpath segments. These measurements can be used objectively to collect and measure factors influencing pedestrian level of service. PLOS scores can be considered as a basis for selecting or developing pedestrian facilities and identifying how well a facility or service operates from a user’s perspective. This study is considered the first attempt in Australia to produce a new PLOS model based on revealed pedestrians’ perceptions. It could be used as a guide for future studies, including real-world application by planners, urban designers and transport engineers. There are some limitations to this study which have implications for further research. Limitations with the sample and the research methods include the following main issues i) the results obtained from the Delphi process do not take into account the perceptions of a broader range of experts; ii) although the pedestrian survey sample was sizeable, obtaining 312 participants for such a lengthy survey, it is not feasible to split the resulting dataset down to key sub-populations; iii) this study’s outputs, and PLOSAT itself, are solely limited to commercial streets in the Australian setting. The tool could be used in a few other select locations, but it is highly specific to this Australian context and does not take into account features of the path environment that are found elsewhere (i.e., North American cities’ problems with snow).