Why Generative Planning? The Non-Convexity Argument Against Regression in Autonomous Driving
The trajectory planner is the decision-making core of an autonomous driving system. Its task: given the current scene, output a future trajectory that is safe, comfortable, and efficient. Most production systems today use some form of regression — minimizing the distance between predicted and ground-truth trajectories. Yet a growing body of research and engineering evidence suggests this approach has a fundamental flaw: it assumes the feasible set is convex when it is emphatically not. This article lays out the first-principles argument for why generative approaches (diffusion, autoregressive) are not merely improvements but necessary paradigm shifts. ...