The National Road Safety Council of Papua New Guinea has raised the alarm about the poor state of taxis and small buses in the capital.
It says between 80 and 90 percent of them are not roadworthy and are being operated illegally, which puts at risk the thousands of passengers that rely on them.
The Council's Executive Director, Nelson Tereme, says despite impounding hundreds of buses and taxies over the years, the owners only pay a fine and continue to operate illegally.
He says Port Moresby will host the South Pacific Games and other important meetings but public transport is appalling.
Mr Tereme says there needs to be some form of harsh penalty for offenders to improve road safety.