Effectiveness of Riyadh's Urban Growth Boundaries: An Evaluation Based on Building Permits, Vacancy, Road Infrastructure, and Land Price Variation

Rapid urbanization in Riyadh has exerted significant pressure on urban growth boundaries (UGBs), raising questions regarding their effectiveness in containing urban sprawl and promoting compact development. This study evaluated the effectiveness of UGBs in Riyadh using an integrated framework comprising three interconnected dimensions. First, we examined whether the UGB effectively directs development within its boundaries by analyzing the building permit distribution and assessing the availability of road infrastructure for permits issued outside the boundary. Second, we investigated whether vacant land inside the UGB is adequately infilled to promote compact growth over time. Third, the dominant spatial factors affecting sprawl patterns and land price variation were identified using Local Moran's I and multiple regression analysis. We demonstrated that some areas beyond the UGB are sustainably developed with adequate infrastructure and can be considered acceptable, with significant vacant land persisting within the boundary. Although UGBs generally have a constrained outward expansion, they do not successfully promote internal compactness. Increasing land prices within the UGB have reduced affordability, encouraged development toward the urban fringe, increased internal vacancies, and reinforced the spatial patterns of sprawl. These results indicated that, without coordinated land use, density, and affordability policies, UGBs alone cannot effectively manage urban growth.