Police report 50 motorway missiles

Police say 50 vehicles have been hit by objects thrown from Auckland motorway overbridges in the past 18 months.

In the most recent case, three cars were damaged and a driver injured when missiles were thrown from an overbridge between Papakura and Drury on Sunday night.

Inspector Dave Walker of the motorways police said 60 per cent of the recorded incidents - where vehicles were damaged but no-one seriously injured - happened on overbridges above the Southern Motorway.

Police beefed up their response to motorway missiles after the death of Chris Currie last August but Mr Walker said those responsible were often not caught.

Mr Walker said a motorway police car was sent to the damaged vehicle and another patrol dispatched to the overbridge. A dog handler and the police helicopter would also be sent if available.

Transit is putting up permanent fencing at the Princess St and Bairds Road overbridge.

Manukau City Council traffic engineer Bruce Conaghan said the council was looking at installing street lighting in problem areas before the end of the year.