A man was arrested today after reports of rocks being thrown off an Auckland motorway bridge, police said.

The 43-year-old, of no fixed abode, would face a charge of endangering transport when he appeared in Auckland District at a time and date to be decided.

Police were called about 11.45am after a man was reported to be throwing rocks off the Bond St overbridge above the North-western Motorway.

The charge of endangering transport carries a maximum sentence of 14 years in prison.

The incident follows others in Auckland over the past month involving items being thrown at vehicles.

Three weeks ago, a 20-year-old Taupo apprentice builder, Chris Currie, was killed when an 8kg slab of concrete was dropped off an overbridge above the Southern Motorway on to his car.

A 14-year-old schoolboy has been charged with Mr Currie's murder.

Five days after Mr Currie's death, a female bus passenger in Mt Albert was hit on the head when a male pedestrian hurled a rock through the vehicle she was in.

The woman was knocked cold but ended up not being seriously hurt. The offender ran off.