Some people have asked whether privately installed "Check Speed" signs are legal. They are, but please note that this is general information only and should not be construed as legal advice. If in doubt consult a solicitor.
Firstly Brydens Law Group of Liverpool, one of Sydney's largest law firms, sponsored the installation of 21 of the signs in the Western Suburbs. They would not have paid out $21,000 or put their name to it if there was any doubt as to the legality of the signs.
Under the Road Transport Act a person must not, without appropriate authority, install or display a prescribed traffic control device on or near a road.
That does not cover all traffic signs, otherwise the thousands of privately installed signs on garbage bins all over NSW that read: “Slow Down in My Street” or similar would be illegal. Those signs, like mine, are legal and do not require written RTA approval because they are not prescribed signs under the Act.
My signs say “Check Speed”. There is no sign anything like that in the Road Rules so by definition they are not a prescribed traffic control device.
There are numerous RTA signs that are not prescribed signs either, such as all advisory and warning signs. That is exactly what these signs are.
Flashing lights are not a prescribed traffic control device, otherwise flashing Christmas lights and flashing lights outside shops and businesses would be illegal in the absence of written RTA approval.
Putting flashing lights on a non-prescribed sign does not turn it into one, any more than putting flashing lights on a "Merry Christmas" sign near a school zone makes it a prescribed traffic sign.
There is in fact no mention of school zone flashing lights anywhere in the Road Rules, so they are not a prescribed traffic control device.
The Act also covers any sign that “might reasonably be mistaken to be a prescribed traffic control device.” Once again it has to be mistaken to be a prescribed sign, meaning a sign that is shown in the Road Rules, not just believed to be an RTA sign.
Ignorance of the law is not a valid defence if the law is broken. The same principle applies in reverse. In other words it is assumed that everyone is conversant with Schedules 2-4 of the Road Rules and knows exactly which signs are prescribed signs and which are not. The words "might reasonably be mistaken to be a prescribed traffic control device" must be viewed in that light. The fact that someone might think the signs are prescribed signs due to ignorance of the Road Rules is irrelevant.
Nobody could reasonably mistake the sign to be a Stop sign or a Give Way sign etc. The only possible prescribed sign that it could be argued the signs could reasaonably be mistaken to be is a School Zone sign.
The signs are all positioned in close proximity to a genuine school zone sign. No reasonable person, seeing the two signs side by side, could possibly mistake the "Check Speed" sign for a "School Zone" sign:
The mere fact that a sign serves the same purpose as a prescribed sign does not mean that it could reasonably be mistaken to be such a sign.