This single still is from the widescreen version of ?Beyond?, one of the Animatrix animated shorts. It has been considerably scaled back from the original material.
In this image, we see a strange truck which tears across the city in the short, to attempt to fix a problem in the Matrix. As to why they did not just materialise directly on top of the problem? Well, in all likelihood, they can?t.
Yes the Agents can take control of individual human elements, but shifting all that mass at once? Plus, the contamination area is unstable, and its safer to just drive up to it. In addition a truck just materialising in a quiet afternoon neighbourhood would take some explaining away.
But, finally, and in line with other explorations of a virtual environment, if it is large and complex, it is often going to be easier to create new content at the fringes, then drive it into position using in-world means, then just trying to pop into existence in the middle. This holds especially true if the rules of the world are set up in such a way as to directly oppose the sudden teleportation from occurring.
Yes, you could as administrators, likely override this setting, and pop in anyway, but, that would likely cause anomalies and artefacts to occur, as subsystems attempt to process new data in ways they were just never designed to cope with.
So, a sufficiently realistic VR attempting to emulate a known real world with discrete physical laws, becomes a real world, in multiple ways, not the least of which is an active discouragement of practices that are strictly virtual.
Link: Animatrix: Beyond