🤖 AI Summary
This work addresses the challenge of simultaneously achieving system efficiency, low communication overhead, safe execution, and scalability in large-scale urban traffic management. To this end, we propose VeloCity, a decentralized spatiotemporal trajectory planning framework that, for the first time, supports arbitrary complex urban road networks. In VeloCity, each connected autonomous vehicle autonomously generates conflict-free, dynamically feasible trajectories that minimize travel time, based on a spatiotemporal slot reservation table provided by local coordinators. The approach requires no scenario-specific customization and integrates distributed spatiotemporal profile optimization with a generic road topology adaptation mechanism. Large-scale simulations in Tokyo, Manhattan, Rome, and Bologna demonstrate significant reductions in both travel time and delay variance, effectively prevent gridlock, and exhibit exceptional scalability and performance advantages.
📝 Abstract
As modern cities face increasingly severe traffic congestion, connected and autonomous vehicles (CAVs) have emerged as a crucial enabling technology for next-generation intelligent traffic management. However, fully realizing this potential is hindered by the limitations of current paradigms. Existing approaches typically optimize localized interactions rather than system-wide efficiency, incur severe communication overhead, or lack the deterministic guarantees required for safe kinematic execution. Furthermore, current multi-agent adaptations are frequently restricted to small predefined scenarios, failing to scale across large and complex urban networks. To bridge this gap, this paper introduces VeloCity, a decentralized multi-agent spatio-temporal mobility profile planning framework designed for CAVs operating in arbitrary urban areas. To minimize vehicles' travel times, VeloCity distributes mobility profile optimization directly to individual CAVs. Vehicles query a localized traffic coordinator for a reservation table, independently compute their fastest conflict-free mobility profile, and reserve their requested space-time slots back with the coordinator. By natively adapting to any arbitrary road topology, the framework manages highly irregular urban areas without requiring scenario-specific tuning, all while guaranteeing collision-free and physically executable vehicle trajectories. Extensive simulations across four large-scale real-world urban maps (Tokyo, Manhattan, Rome, and Bologna) demonstrate the framework's scalability. Compared to established state-of-the-art models, VeloCity yields drastically lower travel times, tightly bounds delay variance, and successfully prevents congestion gridlocks even under extremely high vehicular densities.