Abstract: The present invention is directed to computer-implemented method for controlling an autonomous or semi-autonomous vehicle. A vehicle model is provided and information describing a roadway (301) is obtained. This information is transformed in a Frenet-Serret frame, which defines a curvilinear coordinate space. Then, in the curvilinear coordinate space, a plurality of line segments (306, 307) are defined (3) along the roadway (301), at locations spaced longitudinally along a reference line defining the Frenet-Serret frame. The line segments have respective lengths that extends, each, perpendicularly to the reference line. Next, based on the defined line segments, a space-time corridor (327, 327?, 326?) is determined (5) to obtain a time-dependent space available for the vehicle. Bounds for the vehicle within said time-dependent space are subsequently obtained (6). The bounds define a set of constraints that delimit a plurality of convex space-time objects along the reference line.