Research Article Transportation Research Record 2020, Vol. 2674(1) 205–216 Ó National Academy of Sciences: Transportation Research Board 2020 Article reuse guidelines: sagepub.com/journals-permissions DOI: 10.1177/0361198119896782 journals.sagepub.com/home/trr Forecasting the Quality of Service of Bogota’s Sidewalks from Pedestrian Perceptions: An Ordered Probit MIMIC Approach Jose Agustin Vallejo-Borda 1 , Hernan Alberto Ortiz-Ramirez 1 , Alvaro Rodriguez-Valencia 1 , Ricardo Hurtubia 2 , and J. de D. Ortu ´ zar 3 Abstract A variety of different pedestrian performance or service indicators (PPSI), such as the pedestrian level of service (PLOS), or quality of service (QoS), have been developed to evaluate pedestrian infrastructure. Although modeling approaches vary (e.g., ordinal least squares, scoring system), the great majority use on-site measurable attributes, such as sidewalk width or adja- cent traffic, to estimate the PPSI. However, most of these models have been developed without jointly considering objective and subjective variables and their interactions. This study had two objectives: (i) to develop a model that simultaneously uses objective and subjective variables to estimate the pedestrian perception of sidewalks’ QoS in Bogota, Colombia, and (ii) to identify the interactions between objective variables and pedestrian perceptions of sidewalk attributes. To do so, data was gathered from 1056 users of 30 sidewalks in the city and an Ordered Probit Multiple Indicator and Multiple Cause model was estimated and validated using match score, error distribution, and chi squared test. Using the model, it was possible to cor- rectly forecast the perceived QoS in 26 of the 30 sidewalks, considering the interaction between users’ characteristics and on-site sidewalk measured attributes with four latent variables (sidewalk characteristics, surrounding, discomfort, and externalities) based on pedestrian perceptions. We also proposed guidelines that provide decision makers with the tools to identify which sidewalk attributes actually influence pedestrian perception of QoS. Pedestrian performance or service indicators (PPSI) have been estimated in transportation studies since 1971 (1). These indicators have been defined as pedestrian level of service (PLOS), quality of service (QoS), or satisfaction, and have been calculated using different modeling meth- odologies, including ordinal least squares (OLS), scoring systems, Delphi studies, multiple-criteria decision-making (MCDM), ordered models, and discrete choice models, where a variety of attributes from the built environment have been used as the main independent variables. However, most of these models do not consider the simultaneous use of both objective (on-site measurable) attributes and subjective (user perceptions) variables on the estimation of the different PPSI. Furthermore, these models do not usually consider the interactions between on-site measurable attributes and user perceptions about infrastructure characteristics to calculate the dependent variable. User perceptions can enhance such models and their performance (2). This can improve the predictive power of the tool to estimate the pedestrian infrastruc- ture QoS. Given that including user perceptions and their inter- actions with on-site measurable attributes in a model is a strategy to obtain more information on the PPSI estima- tion, the objectives of this study were: (i) to develop a model that simultaneously uses objective and subjective variables to estimate the pedestrian perception of the QoS of sidewalks in Bogota, Colombia; and (ii) to iden- tify the interactions between objective variables (related to the infrastructure) and pedestrian perceptions about 1 Urban and Regional Sustainability Research Group, Universidad de los Andes, Bogota ´, Colombia 2 Department of Transport Engineering and Logistics, Instituto Sistemas Complejos de Ingenierı ´a (ISCI), Centre for Sustainable Urban Development (CEDEUS), Pontificia Universidad Cato ´lica de Chile, Macul, Santiago, Chile 3 Department of Transport Engineering and Logistics, Instituto Sistemas Complejos de Ingenierı ´a (ISCI), BRT + Centre of Excellence, Pontificia Universidad Cato ´lica de Chile, Macul, Santiago, Chile Corresponding Author: Alvaro Rodriguez-Valencia, alvrodri@uniandes.edu.co