IF in doubt, ask a policeman. That is a maxim with which many of us were raised.

These days, perhaps one should consider whether certain qualifications should apply. What if a) one is driving a vehicle; b) one halts said vehicle in the environs of an airport, and c) the officer is in question is armed, and could be considered to be in anti-terrorist mode?

That was the set of circumstances which pertain to the case of Jim Kirkwood, a former officer with the old Strathclyde Special Branch. He stopped on the clearway outside Prestwick Airport, intent on asking police for directions. He was promptly issued with a fixed-penalty notice.

Mr Kirkwood, now £30 out of pocket, is aggrieved. One can also feel some sympathy for the officers. Airports are sensitive areas, especially if one recalls the Glasgow attack of 2007. But one certainly ask the question of whether discretion could have been applied.

There have been many complaints since the formation of Police Scotland that officers have been losing those powers of deliberation, under a perceived target-driven culture. Yet last year Chief Constable Sir Stephen House signalled that he wanted his officers to give more verbal warnings to motorists.

The issue of the nature of policing is, and will continue to be, a vexed one, as this incident highlights.