Trajectory Validation for Autonomous Driving

A method of determining whether a planned trajectory of a first vehicle over a road along which the first vehicle and a second vehicle are traveling, is invalid, comprising: obtaining the planned trajectory, comprising a first state of the first vehicle for each of a plurality of time instants; obtaining a second state of the second vehicle for each time instant; determining, for each time instant, a respective lateral range extending from the second vehicle; and determining that the planned trajectory is invalid where, for the first and second states at one or more of the time instants: the first vehicle is within the lateral range and within a lane boundary region of the road; and a direction of a lateral velocity of the first vehicle is towards the second vehicle and a lateral acceleration of the first vehicle away from the second vehicle is smaller than a predetermined threshold.