Balancing traffic efficiency and ecosystem services in road network planning: A spatial multi-objective optimization...

Road networks significantly affect ecosystems by causing habitat fragmentation, pollution, and land-use change. While previous studies have evaluated these impacts, few offer decision-support tools for minimizing environmental damage during the planning stage. This study introduces an integrated model combining InVEST and NetworkX to optimize road network design before construction. Applied to Mengyang, Xishuangbanna, the model identifies Pareto-optimal road schemes and reveals a trade-off between global efficiency (GE) and habitat quality (HQ). For example, a 0.6% GE loss yields a 1.44% HQ gain, while a 10.9% GE reduction leads to a 4.0% HQ improvement. Central road segments are consistently retained due to high GE and low ecological cost, whereas peripheral roads are often excluded for offering limited efficiency and higher ecological risk. The model also highlights high-conflict zones in transitional areas, emphasizing the need to balance land-use complexity, ecological sensitivity, and development needs. To the best of our knowledge, this study is among the first to integrate an InVEST-based ESs evaluation into the road network decision-making process at the planning stage. The flexible framework can be extended to include additional objectives such as cost, equity, or climate resilience, making it a practical tool for sustainable infrastructure planning across diverse landscapes.