A 34-year-old Serbian citizen was detained at the Tabanovce border crossing, on his way out of the country. The reason has nothing to do with anything he did at the border - it is what he did twice before, on the A1 motorway near Demir Kapija, where the Safe City camera system dutifully recorded him.

On 22 July, at 13:42, he was driving 163 kilometres per hour. On 20 August, at 19:40, on the same stretch, 169 kilometres per hour. The speed limit there is 80. So: double, and then some.

What makes this case more interesting than an ordinary traffic offence is that it shows how the cameras work - and also where they stop working. The driver was recorded in July. Then again in August. And only when he set out to leave the country, on 29 August at 23:20, did somebody finally stop him. More than five weeks passed between the first recording and the arrest, and in that time the same man returned to the same stretch of road and did the same thing again.

According to the Interior Ministry, this falls under Article 297-a of the Criminal Code - "reckless operation of a motor vehicle". Not a fine-and-drive-on infraction; a criminal offence. And yet, between the two recordings, nobody stopped him from cruising the A1.

Demir Kapija is not a random stretch of road. It is the part of the motorway where the limit was dropped to 80 precisely because the geometry of the road does not forgive mistakes. A vehicle doing 169 there is not a statistic - it is a potential funeral procession for whoever happened to be in the next lane.

The driver was taken to the Negotino police station and criminal charges will be filed. Fine. But the question the cameras do not answer on their own remains: how many drivers were recorded today who will only be stopped when they head for the border - or never at all?