The scaffolding fell off a truck travelling on the Calder Freeway towards Melbourne near Black Forest Drive in Macedon just after 7am, according to police.
Many drivers were forced to pull over to the side of the freeway, with their cars having suffered damage, including tire punctures.
No one was injured.
A truck driver stopped at the scene.
Police are speaking with the driver and investigating what happened.
Any witnesses or anyone with dashcam footage is urged to contact police.
