Interpose
Sometimes we might want to move a vehicle between two agents, for instance trying to block a pass between opposing players in soccer. The interpose behaviour does this by calculating the steering force needed to move the vehicle to the midpoint of an imaginary line connecting the two agents.
Like pursuit we must estimate the future positions of the agents, the look-ahead time is the fastest time (travelling at maximum speed) to reach the current midpoint. This is used to estimate the future agent positions and the future midpoint indicates the desired velocity, from which we calculate the steering force using the arrive behaviour.
The interpose behaviour can also be used to move between an agent and a fixed location, or between two fixed locations.