A Dunedin man charged with interfering with transport after diverting motorists from a breath testing checkpoint put himself, drivers and officers, at risk - but appeared to think he was doing a good turn, police say.

Acting Sergeant Tim Coudret, of Mosgiel, said a breath testing team was set up in the northbound lane of Cumberland St (State Highway 1) outside the Leviathan Heritage Hotel about 10pm on Saturday.

Some drivers coming through the checkpoint commented their road cone placement was “pretty average”, Coudret said.

Subsequent inquiries revealed a line of road cones, taken from a contractor’s site at the carpark opposite Queens Gardens, had been placed across the road, diverting traffic along Queens Gardens and Burlington St.

Chalking the impromptu traffic management down to the behaviour of “some drunk idiot”, officers removed the cones and resumed the checkpoint, Coudret said.

While officers had spotted a man running off, they were unable to identify him.

It was not long until the same thing happened again, with the man again fleeing promptly.

Expecting it would happen a third time, Coudret decided to wait behind a car.

Soon afterwards, he saw the man setting up the cones and he gave chase across Queens Gardens into Vogel St.

After losing sight of the man, officers combed the area. Within 15 minutes, they saw the man wandering on the southbound side of Queens Gardens wearing different clothes.

Officers once again gave chase, and caught the man outside Toitū Otago Settlers Museum, where he tried to hide in the bushes.

The incident was “a bit comical, but a massive risk to us and the public”, Coudret said.

Some cars ended up going around Queens Gardens in circles as they had no other option to go north.

It appeared the man had an aversion to police stopping traffic and was trying to do what he thought was a good deed, Coudret said.

Senior Sergeant Anthony Bond, of Dunedin, said a 45-year-old man had been charged with interfering with transport in relation to the incident.