An Auckland taxi driver is pleading for barriers on motorway overbridges after his car was hit by a large rock.

Avtar Singh says six or seven kids were on the bridge over the State Highway 20A link to the airport when the rock was hurled on Friday evening.

It hit his bonnet.

The 30-year-old said if he hadn't seen it coming and taken evasive action, it may have smashed through his windscreen - and he fears that could have killed him.

Mr Singh said there is a clear immediate solution.

"Put the barriers around the walking bridges, otherwise we have no other option."

He said this has been a regular occurrence with similar incidents reported by other taxi drivers several times over the past month

Mr Singh said he will now slow his car on the motorway as he approaches overbridges, to check if there is anyone on them before he continues driving.