Photo by Gregor Richardson.
Organisers stopped 15 cyclists in as many minutes to inform them about the campaign.
Mr Cosgrove said he commuted by bicycle ''most days'', and he ''always wears high-vis [gear]''.
He had never had an accident, but had had ''a few near misses'' in his six years of daily cycling.
Former Olympic mountain biker Kashi Leuchs, of Dunedin, who now runs a bike shop in Dunedin, also took part in the event.
Yesterday was the first time he had participated in the campaign, he said.
''I like to encourage other people to cycle,'' he said.
''I wanted to help promote cycle safety.''
