Several speed limit signs on the main road between Newcastle and Sydney have been defaced with what appears to be a political message to end the NSW school holidays.
A NSW Police spokesperson confirmed the agency was aware of the vandalism on the M1 Pacific Motorway - which involved 110km/h speed limit signs being changed to read "NO".
The defacing of the signs came amid the end-of-holiday jam on the motorway, which is the most popular route for motorists travelling between Sydney and the north coast.
It also took place a week out from the referendum on the Indigenous Voice to Parliament.
NSW Police said speed signs had been tampered with on the motorway between Newcastle and Hornsby at the weekend, with the damage coming to the attention of authorities on Sunday.
Several images of the vandalism were circulating social media, captured by bewildered travellers.
Police have notified the NSW Transport Management Centre, which was in the process of correcting the signs at the time of publication.