Application of Integrated UAV and TLS Point Clouds in Urban Road Renovation Design: A Case Study of Xiangjiang South Road Scenic Corridor in Changsha, China

Abstract

Urban road renovation projects often face complex site conditions, incomplete elevation information, dense roadside facilities, and limited support from conventional two-dimensional topographic data. To address these issues, this study investigates the integrated use of unmanned aerial vehicle (UAV) photogrammetry and terrestrial laser scanning (TLS) for 3D modeling and renovation design of an urban road corridor. The study area is Section B of Xiangjiang South Road Scenic Corridor in Tianxin District, Changsha, China, where the existing road is narrow, partially damaged, and characterized by mixed motorized and non-motorized traffic. The redesigned corridor is 871.861 m long, classified as an urban secondary arterial road, with a design speed of 40 km/h and a standard cross-section width of 16.5 m. UAV and TLS data were acquired and processed to generate integrated point cloud products for terrain correction and design support. The results show that the integrated point cloud data effectively improved the representation of existing terrain and roadside geometric conditions, especially in areas where the original topographic map contained sparse or unreliable elevation information. The combined dataset provided both corridor-scale terrain continuity and detailed local geometric features, which supported route design, vertical profile design, cross-section definition, drainage layout, pipeline coordination, and lighting design. Compared with a single data source, the integrated use of UAV photogrammetry and TLS provided a more practical 3D basis for road renovation in a constrained urban environment. The study demonstrates that multi-source point cloud technology can serve not only as a visualization tool, but also as an effective pre-design support dataset for urban road renovation engineering.