The person believes they may have been caught by the camera for going at 50 km/h and the speed limit may have changed to 40 km/h.

Checking recent YouTube videos and Google Maps (Street View and Satellite View) still have the speed limit at 50 km/h. The speed limits according to the person's GPS device was still stated as 50 km/h.

According to the Transport for NSW site there's a notice on the 28th of May 2020, the speed limit in Oxford Street from Flinders Street to College Street will change to 40 km/h from 50 km/h and take effect in the next two weeks once the signs have changed.

In the past I have read and heard of people getting booked when they aren't aware of a speed limit change. There's usually quite a high extra revenue generated until people become aware of the new speed limit restriction.

In the past, if I recall correctly, I've read for Victoria there's 14 days noticed before people are fined. Victoria is particularly bad a sign posting speed limits, whereas from a Victorian's point of view NSW is much better. In the case of Oxford street you'll see speed limits painted on the road, speed signs and then before speed cameras you'll see a warning sign with the current speed limit. Of course that doesn't mean you'll see the information if there's heavy traffic and buses or trucks blocking your view.

Kelvin Eldridge