Understanding accessibility through public transport users' experiences: A mixed methods approach

Highlights

• We found interrelation among accessibility barriers, especially between vulnerable people

• We found a ‘hidden’ value for buses, particularly among public transport users

• We identified different ‘socially constructed’ narratives for buses and metro

• We found a dissimilar perception of transport environment by gender, age and location

• We measured different accessibility profiles for the various public transport users

Abstract

The quantitative measurement of accessibility through public transport has become more complex and accurate over time. However, it lacks many of the deeper nuances of how people actually experience their travel environments. Our previous works have highlighted the importance of incorporating the lived travel experiences of passengers within accessibility indicators, considering the quality of the walking environment and different attributes of the public transport services.

Building on these works, this mixed-method research seeks to further improve the characterization of accessibility according to users' travel experiences, as described by those attributes that inhibit or enhance access to opportunities within the city. We use content analysis of focus groups, data gathered in a brief survey and sociodemographic and public transport data for our analyses. Our main contributions are (i) to develop a conceptual framework to analyze qualitative data on how people relate and discuss their public transport accessibility experiences and (ii) to develop accessibility indicators differentiating user perceptions. We apply this novel conceptual framework and methods to the unique urban morphology of two municipalities of Santiago de Chile.

We identified different ‘socially constructed’ narratives for buses and metro. The participants focused on barriers to accessibility, showing an important relationship between them, as well as substantial differences in their overarching positive perception of metro and negative for buses. However, when disaggregating the analysis by primary transport mode and location, we found ‘hidden’ values for buses, recognizing its capillarity and underlying connectivity with the metro system. Furthermore, we found a dissimilar perception of transport environments when disaggregating the analysis by gender, age and location, which translated into different accessibility profiles for the various public transport users. From these experiential qualitative perspectives, it was thus possible to determine some attributes that had been previously overlooked in more quantitative studies but which are important when analyzing public transport accessibility for different population groups.

Introduction

Innumerable theoretical and methodological advances in accessibility have already been developed in the last decades, associated with its conceptualization, measurement and (less so) its operationalization in practice (Papa et al. 2016; van Wee 2016). Notably, the quantitative measurement of accessibility through public transport has become more complex and specific over time. This is partly thanks to the greater availability of smart-card and general transit feed specification (GTFS) data, and partly due to the improved robustness of the methods to include elements such as congestion, real-time bus schedules, daily changes in travel times, service opening hours, among others (Weber and Kwan 2002; Delafontaine et al. 2011; Neutens et al. 2012; Fransen et al. 2015). However, many of the deeper nuances of how people experience their travel environments are not usually included in the accessibility analysis.

In this paper, we discuss perceptions of public transport as these are shaped by common beliefs and narratives or people's experiences, based uponthe practical knowledge gained from doing, seeing or feeling something. In the urban transport context, accessibility and mobility-related built environments are perceived in a certain way by different users and how their individual and collective travel experiences shape their perceptions. Several studies include perception variables within choice models (see for example Bolduc and Alvarez-Daziano (2010) with the inclusion of attitudes, perceptions and opinions as latent variables in Hybrid Choice Models) or public transport satisfaction and loyalty (see van Lierop et al. (2018) for a comprehensive review). However, there is still scarce literature on the inclusion of perception in accessibility studies (see Lättman et al., 2016a, Lättman et al., 2016b for contributions on the field), i.e., how to incorporate it within the analysis, how close are the perceived accessibility and “objective” accessibility measures and how perception could shape different accessibility measures.

Our previous studies have highlighted the importance of incorporating passengers' travel experiences within accessibility analysis, considering the quality of the urban environment where people walk to public transport stops (Tiznado-Aitken et al., 2018) and users' perceptions of the level of service attributes, considering an in-vehicle time equivalence (Tiznado-Aitken et al., 2017). Nevertheless, other key elements still need to be explored more in-depth in order to improve the characterization of accessibility according to different users' travel experiences. This paper explores the use of qualitative methods to further improve the characterization of accessibility experiences as a function of attributes that inhibit or enhance users' accessibility to opportunities within the city. Besides the financial, physical, temporary and organizational barriers (Cass et al. 2005), we highlight barriers linked to a disparate perception of the mobility-related built environment. Due to spatial and socio-demographic heterogeneity, this perception differs among inhabitants, having a direct impact on the perceived access within the city and, consequently, the exclusion that these groups can experience.

We propose a conceptual framework and a qualitative methodology to analyze accessibility, focusing on how people relate their public transport accessibility daily experiences. We apply our method to the geographical context of two municipalities of Santiago de Chile, an interesting case study since it is a city with quite a good public transport system, including an integrated fare, but also with some key features typical of Latin American cities, such as high socio-spatial inequalities and a marked car-centered urban planning in the last few decades, despite most of its population not having access to cars (SECTRA, 2015).

Thus, using content analysis of focus groups, data gathered in a brief survey and socio-spatial analysis, we raise relevant issues within the traveler experience, generating qualitative concepts or labels for perception and narratives of the transport environment. Based on our findings and to enrich our paper, we include a quantitative analysis of the public transport trips and how different are perceptions of walking times and crowding conditions for people of different ages, income and gender. This analysis was translated into four public transport accessibility maps for different user profiles, which evidence gaps in terms of generalized travel times and, therefore, accessibility to opportunities in the city. From these ‘real world’ experiences it is thus possible to determine some overlooked attributes that should be considered when analyzing accessibility through public transport for different population groups.