Reliable and Real-Time Highway Trajectory Planning via Hybrid Learning-Optimization Frameworks

TL;DR

This paper introduces a hybrid trajectory planning framework for autonomous highway driving that combines learning-based adaptability with optimization-based safety guarantees, ensuring real-time, reliable, and collision-free trajectories.

Contribution

It presents a novel hybrid framework that integrates a learning module with MIQP optimization, enabling real-time, safe, and adaptive highway trajectory planning.

Findings

Achieves over 97% success rate on HighD dataset scenarios.

Average planning cycle time is approximately 54 ms.

Ensures collision-free, smooth, and kinematically feasible trajectories.

Abstract

Autonomous highway driving involves high-speed safety risks due to limited reaction time, where rare but dangerous events may lead to severe consequences. This places stringent requirements on trajectory planning in terms of both reliability and computational efficiency. This paper proposes a hybrid highway trajectory planning (H-HTP) framework that integrates learning-based adaptability with optimization-based formal safety guarantees. The key design principle is a deliberate division of labor: a learning module generates a traffic-adaptive velocity profile, while all safety-critical decisions including collision avoidance and kinematic feasibility are delegated to a Mixed-Integer Quadratic Program (MIQP). This design ensures that formal safety constraints are always enforced, regardless of the complexity of multi-vehicle interactions. A linearization strategy for the vehicle geometry substantially reduces the number of integer variables, enabling real-time optimization without sacrificing formal safety guarantees. Experiments on the HighD dataset demonstrate that H-HTP achieves a scenario success rate above 97% with an average planning-cycle time of approximately 54 ms, reliably producing smooth, kinematically feasible, and collision-free trajectories in safety-critical highway scenarios.