DP has summed it up much better than I did a lot of posts ago. Mayday/Pan procedures with ATC for fuel shortage etc can remain unchanged BUT outside services response will be arranged comensurate with need. How this would be organised I don't know, but the issue should certainly be aired at the inquest on the unfortunate motorist, and ideally now. A similar incident occurred some years ago near L'pool Airport when a police car attending a minor incident collided with another car, fortunately without serious injury.