Mobility Gains and Territorial Costs: Transportation Infrastructure as Drivers of Urban Regeneration, The Case of Constantine

This study examines the combined effects of the tram and the Salah Bey Bridge on mobility and urban restructuring in Greater Constantine the area between the Tell and the Hautes Plaines which faces congestion in its downtown area. Unlike other studies, this one analyzes two infrastructure projects of different types and their contribution to territorial transformations. The analysis is based on three levels. The first describes the infrastructure: the tram, which began operating in 2013 and was extended to the new town of Ali Mendjeli in 2019, structures the southern axis of Greater Constantine over 18.5 km; the Salah Bey Bridge, which opened in 2014, connects the Mansourah Plateau to the central districts. The second compares, using Google Maps, two routes between the same origins and destinations: via the traditional routes of National Roads 79 and 5, or via the bridge. Estimated travel times decrease by 23% on the route via National Road 79, from 13 to 10 minutes, and by 39% on the route via the RN 5, from 18 to 11 minutes. Finally, based on satellite imagery available for 2013, 2020, and 2025, the analysis examines changes in land use around the three stations along the agricultural section between the administrative boundary of Constantine and Ali Mendjeli. A circular buffer zone with a radius of 500 m is defined around each station. The results reveal spatial variation: the proportion of built-up areas ranges from 30% to 65% in a first zone favoring spontaneous urbanization and unregulated subdivisions from 15% to 30% in a second zone, where agricultural land remains predominant, and reaches 70% in a third zone following an increase since 2013. These infrastructure projects go beyond their transportation function by increasing accessibility and land-use pressures, which calls for better coordination between transportation, land-use management, and urban planning.