To distinguish them from more
relevant obstacles on roads like moving cars, traffic islands
or construction zones, each obstacle is categorized as being
either OFF-ROAD, NEAR-ROAD or ON-ROAD. This is done
by the sensor layer as each obstacle is checked for its distance
to the nearest road segment. Thus, data points received by
the behavioral executive are already filtered as relevant and
irrelevant and only relevant points near or on-road need to be
checked for collision checks with trajectories along the roads.