Sustainable Project Planning in Hilly Terrain

Construction in hilly and environmentally sensitive regions is very different from building on flat land. Steep slopes, limited road access, frequent weather changes, and strict environmental rules constantly disrupt project schedules. Because of these challenges, traditional planning methods often fail, leading to delays, cost overruns, and unsafe working conditions. Recent research shows a major shift toward smarter and more flexible scheduling methods supported by digital tools, spatial data, real-time monitoring, and sustainability-based planning. This review brings together key findings on how construction projects in hilly regions can be planned and managed more effectively. It highlights how modern scheduling software, terrain-informed planning, productivity modelling, environmental timing windows, and circular-material workflows can significantly improve project delivery. The review ends with an integrated framework that connects terrain conditions, digital tools, environmental needs, and project performances showing how better scheduling can lead to safer, faster, and greener construction.