Designing and implementing a geographic information system-based tool to support walking

Abstract

Introduction: Increasing duration and frequency of individuals’ walks as a mode of transportation in their daily lives provides significant environmental, economic, and personal health benefits. The built environment plays a key role in encouraging or discouraging walking. The identification and quantification of the built environment features involved constitutes the base of Walkability Indices (WI). Previous investigations by scientists into WI sought to rank urban areas according to how suitable to walking their environments were, at different scales and levels of spatial detail, generating fixed, constant values. Most WIs found in the literature do not take into consideration comfort aspects such as noise pollution and shade/sun conditions. Because other studies have emphasized the significance of taking into consideration comfort conditions that matter to individuals while walking, we took the decision to incorporate these conditions into the design of a new geographic information system (GIS)-based WI. Determining the relative weight of each WI factor has been the subject of discussion and previous studies assessed it differently. From this point of view, determining these weights will be challenging, especially with the inclusion of new factors for comfort conditions. Moreover, because comfort conditions are always changing, incorporating them into the computation of WI would result in dynamic values. Therefore, it is essential to automate the calculation of that WI, which could then be used to find compatible comfortable walking routes. A significant number of web-based services and mobile applications have been developed to help people to plan their trips using different transport modes. These services and application consider walking mode as a secondary action connecting the other modes. From this perspective, they only optimize the duration and/or distance to reach the destination. Because previous route planners did not include comfort conditions and user preferences inside their walking mode, they were unable to encourage individuals to walk more and so improve their health. Hypotheses: This research is based on these two pieces of evidence. First, regular walking is beneficial to people's health. Second, encouraging individuals to take more daily walks can be achieved by providing high-quality walking experiences. We hypothesize that advanced GIS programming techniques can find for walking both desired built-environment features and comfort conditions. We specify the hypothesize in three parts. First, walking suitability in some sections of built environment changes spatially and temporally when considering comfort factors. Second, the preferred route for walking differs based on people's perceptions of current comfort conditions and the purpose of walking trip. Therefore, personalizing the finding of walking routes can satisfy to pedestrians and therefore improve the quality of walking trips. Third, more people would use mobile applications than complex computer software to plan their preferred walking routes. Objectives: The aim was to gain a deeper understanding of how the configuration of the urban environment effects the amount of time we spend walking and therefore our health. As part of the process conducing to it, we considered creating a new WI and using it to determine pedestrians' preferred walking routes via a mobile application. The main objective of this dissertation is to develop a GIS-based method that aids in pleasant walking route planning in built environments, with the intention of improving public health. This objective is achieved by the following specific objectives: 1. To develop a dynamic WI which is possible to compute without the need for field work and includes comfort factors (noise and sun/shade conditions) that encourage or discourage walking. 2. To design a GIS-based algorithm to automate the computation of a highly detailed, customized WI and to propose a route planner that incorporated walking comfort parameters based on real-time contextual data. 3. To develop a mobile application providing best routes incorporating realtime walking comfort parameters. It facilitates the planning of a comfortable walking route, and thus make it more enjoyable. Methods: The city of Madrid was chosen for this study because of its size, its availability of the necessary data bases, and the fact that was proven as a useful living laboratory in previous studies related to Public Health and walkability. For the first objective, we relied on the official secondary data sources to obtain data of the WI factors. The sidewalks used as the spatial observation unit. Experts’opinions were consulted to assess the relative importance of each factor. In brief, this WI’s properties were based on secondary sources, spatially detailed, dynamic, weighted, and including comfort-related factors. For the second objective, we customized the calculation of WI and included realtime data for comfort conditions in it. Likewise, we overcame challenges to repeatedly create 2D shades of Madrid’s buildings shadows and create a line-based routes network on sidewalks. Finally, we designed and tested a GIS-based algorithm to automate WI computation and find a comfortable walking route. For the third objective, we designed and evaluated a mobile route planner called Pleasant Walk (PW). This route planner was linked to the previous GIS-based algorithm, so that the average person can operate that algorithm. Results: For the objective 1, we analyzed the experts’ opinions, which allowed us to determine the relative weights of the WI factors. Then, using WI factors and relative weights, we calculated WI values on the sidewalks of the city of Madrid at different times and revealed that including comfort conditions converts WI into a dynamic index. For objective 2, we leveraged on the WI concept that we had already developed and made use of the most current weather data. It resulted in the design of a complex algorithm that made possible the automation of the process conducing to the computation of the sought customized, real-time WI. In the algorithm's subsequent stage, we analyzed a pedestrian route network using WI values that allowed us to propose a comfortable walking route. For objective 3, we relied on the previous algorithm as the base for PW, a mobile walking route planner for Android phones. PW enabled the conversion of individually computed WI into proposed routes that maximized the user’s personal comfort conditions. This PW application constituted the tangible product example of transferring research findings to society. Conclusions: This thesis describes a GIS-based methodological development that has enabled two significant achievements through the application of advanced geoprocessing techniques. First, characterizing and quantifying the walkability conditions of the city of Madrid with great spatial detail and under customized simulation conditions. Second, the development of Pleasant Walk, a mobile application that is an example of how research results in Health Geography are transferred to society. Personal comfort parameters related to noise level, actual temperature and true insolation of the sidewalks have been considered in the WI developed in this research. The research as a whole led to the following conclusions: - Considering comfort factors in the calculation of WI changes its values at different times of the day and during the seasons, thus making the WI dynamic. - The GIS-based algorithm developed in this study can automate the calculation of the WI. therefore, each time it is calculated, its values include actual user's preferences and real-time comfort data. - Any other city with a level of SDI similar to Madrid can apply the same methodology to produce a useful, inexpensive, rapidly computed, and detailed WI. - Creating a network of sidewalk routes and casting building shadows of massive spatial data are topological and geoprocessing challenges that have been overcome by the novel methods presented in this study. - Our route planner PW for mobile phones represents a significant qualitative leap in WI research by allowing us to transfer our recent advances in WI investigation to the general public. In addition, PW has the potential to raise the amount of time people walk each day, hence improving public health. - This dissertation is an example of multidisciplinary research on the subject of encouraging walking in built environments. Supporting walking activity is a strategy advocated in developed countries in order to address remarkable global challenges such as health, pollution and energy.