Gday all,
 
As an 'outsider' i've never understood why SA has 25kph roadworks/school zones. I understand their merit in SOME situations, but it seems that most of the time they are used in place of the 40kph signs, this is just ridiculous.
 
This got me thinking, i remember seeing somewhere that Australian Design Rules state speedometers need to be accurate from 40kph. I've found some documentation about this. Seen below.

From what i can gather, there is no specific testing done below 40kph. as such there is no guarantee that it is accurate at all. the leeway for 40kph is 8kph.
(between 0 and 0.1*40 + 4kph)
= 4 + 4kph 
 
and at 25kph - 6kph leeway.
 
thoughts?
 
(my theory is that there was a mistake in the conversion process between mph and kph. 25mph = exactly 40kph. coincidence?)
 

zmit
 (my theory is that there was a mistake in the conversion process between mph and kph. 25mph = exactly 40kph. coincidence?)

Don't think its a coincidence, just this state being backwards as usual...still stuck in 1960s thinking...

yep have to agree with josh here, nothing can be seen as 'wrong' by people that run this state, so what worked decades ago, should still remain in their eyes..

Welcome to the backward state, the granny state, the police state you name it state including the most expensive state for electicity in the WORLD.
This is the way it is here in good ol' SA.
For example if you ever go up O'Connell St  North Adelaide look at the vacant land that is on that street. This used to be the Lecornu building until they sold it about 30 years ago.
The building was demolished and many applications have been made to put in shopping etc but no-one wants to make a decision. Everything that is submitted gets knocked back.
So the vacant area is an eyesore but who cares as long as the powers  to be can dictate what they like.
But there are some good things about this state.
You do not have to have a yearly inspection for roadworthiness. What is done here is that the police pull cars over at random and give them a roadworthy check. 
The RAA thinks this is a better method than an annual inspection as it picks up unroadworthy cars at any time and gets them off the road.
That is my two bits worth
PS I have lived in SA for about 60 years.
 
 

Not wanting to keep bashing on but if the Metropolitan Adelaide Transport Study (MATS) plan was implemented and not canned, we wouldn't have any of the worsening traffic congestion we have now.  We are really the only capital city in the country without ANY inner-urban freeways. Every main road during peak hour is a crawl to the next red light... 
But yeah its not all bad, the twisties are fantastic and on my doorstep and its clean and generally a safe place.