Reminding drivers of their responsibilities in local areas

The City of Port Phillip is supported by Road Safe Inner Melbourne in deploying this speed trailer around the municipality at locations where residents have raised concerns about traffic speeds.
It is currently working on Todd Road near the Boulevard, where the display shows that the vehicle which has just passed was travelling at 57 kph.
It seems to be news to some drivers that 50 kph is the default speed limit unless otherwise signed.