Civil Engineering and Architecture 11(2): 948-985, 2023 http://www.hrpub.org DOI: 10.13189/cea.2023.110231 Constructing an Analytical-based Model for User Satisfaction towards Under Bridge Spaces within the Egyptian Urban Fabric Y. Sarhan 1,* , H. Elfouly 2 1 Department of Building Technology, Architecture and Urban Design Program, German University in Cairo (GUC), Egypt 2 Department of Urban Design, Faculty of Urban and Regional Planning, Cairo University, Egypt Received October 25, 2022; Revised December 28, 2022; Accepted January 10, 2023 Cite This Paper in the Following Citation Styles (a): [1] Y. Sarhan, H. Elfouly , "Constructing an Analytical-based Model for User Satisfaction towards Under Bridge Spaces within the Egyptian Urban Fabric," Civil Engineering and Architecture, Vol. 11, No. 2, pp. 948 - 985, 2023. DOI: 10.13189/cea.2023.110231. (b): Y. Sarhan, H. Elfouly (2023). Constructing an Analytical-based Model for User Satisfaction towards Under Bridge Spaces within the Egyptian Urban Fabric. Civil Engineering and Architecture, 11(2), 948 - 985. DOI: 10.13189/cea.2023.110231. Copyright©2023 by authors, all rights reserved. Authors agree that this article remains permanently open access under the terms of the Creative Commons Attribution License 4.0 International License Abstract A successful Public space has been addressed mainly by functional performance, accessibility, comfort, safety, pleasure, and meaning; the five physical attributes constructing the public space index, which was associated with vitality and user satisfaction. Under-bridge public spaces, although they are a booming essential topic in the shadow of the massive bridge construction inserted in the Egyptian urban fabric, they are not well investigated concerning user satisfaction nor the new developed physical setting. Only limited literature highlighted that the “Accessibility” attribute should be considered. Considering under-bridge spaces as a case-specific public space with potential, yet not reflecting the general norms of public space, this paper aims to study user satisfaction towards such spaces. Firstly, a theory-based model has been developed for user satisfaction towards public spaces, exploring the significance of the above mentioned physical attributes. Secondly, adopting a case-study approach, the physical attributes of the theory-based model have been assessed in Heliopolis, a district that recently received a massive under-bridge construction in Egypt, where those attributes have been measured quantitatively (using GIS) and qualitatively (using the developed Public space index and adopting a structural equation model using SPSS & Smart SPLS); to ultimately construct an analytical-based model for assessing the significance of the physical attributes responsible for the user satisfaction of such specific spaces. Results show the misfit between the theory-based model and the induced “analytical-based model of under-bridge spaces”, where “Accessibility” and “Functionality” attributes were relatively insignificant, while the most related attribute to under-bridge user satisfaction was “Safety,” followed by “Comfort”; then “Pleasure” and “Meaning,” a key factor to be considered while developing under-bridges public spaces. Keywords Under-bridge Spaces, Leftover Public Spaces, Public Space Index, Public Space Vitality, User Satisfaction Level, Public Space Physical Attributes 1. Introduction Given the rapid population growth, increased number of car-oriented users, the continuous expansion of new cities, and the enlargement of the urban development mega projects, Egypt has witnessed a remarkable infrastructural development, resulting in the construction of a vast number of bridges in the urban fabric [1]. Reaching 2792 bridges, according to CAPMAS [2], has resulted in the generation of multiple under-bridge spaces, which have been considered an essential issue to be resolved [3]. Consequently, Egypt authorities have started to develop community spaces under the newly constructed bridges as mentioned in the Strategic Urban Development Plan for the