Thabo Tsholetsane, the acting executive manager of the Road Traffic Management Corporation (RTMC), was speaking at the launch of Operation Juggernaut - a campaign focused on eliminating unroadworthy vehicles from the country's roads.
He said government was "doing a study" to see how often roadworthiness tests could be done.
Asked if RTMC was thinking of implementing a statutory roadworthiness testing requirement for ageing vehicles, Tsholetsane said that heavy duty lorries as well as public transportation vehicles were currently required to undergo a roadworthiness test every year.
"With 7.3 million vehicles on the country's roads we may not be in a position to test these vehicles. We have being doing a study to see if these tests can be done.
"I suspect if this (mandatory roadworthiness testing) does happen, it will be done every two years," he said.
Launching Operation Juggernaut, Transport Minister Jeff Radebe said that between 10% and 15% of all fatal crashes in the country involved unroadworthy vehicles.
He said the operation would be implemented during February and would become a part of the transport department's Rolling Enforcement Plan.
While he welcomed the decrease in lives lost during the recent festive season, Radebe said that on average 36 people were killed every day on the country's roads.
Operation Juggernaut would also ensure that traffic authorities nationally would be able to stop and check 200 000 public transport and freight carrying vehicles, Radebe said.