Don't get me wrong - there's a good reason for 50km/h limits. It's just that in my experience some roads that are default arterials have also been posted 50 and guess where the mobile speed cameras tend to park?
Anyhow, from a Victoria Parliament report here's some facts on the introduction of 50km/h limits:
http://www.parliament.vic.gov.au/rsc/speed/speed.htm
/QUOTE/
The Municipal Association of Victoria (MAV) focused solely on the 50 km/h general urban speed limit proposal. It presented the results of a survey of councils the Association conducted in February 1994 which showed support for a 50 km/h limit from:
* Fifty Melbourne metropolitan councils (with 4 against and 3 no responses);
* Ten provincial city councils (8 against; 19 no response); and
* Nine rural councils (11 against, 91 no response).
On the basis of the survey the Association asked the Minister for Roads and Ports to adopt a staged approach to introducing a 50 km/h limit, starting in Melbourne and extending to the provincial cities and rural towns 'in line with local support'. The Association stated that a formal response had yet to be received from the Minister but informal advice indicated no change in the Government's position of not implementing a lower general urban speed limit.
/UNQUOTE/
So, there isn't widespread support so what we'll do is start it in areas where support is acceptable and then force it on everyone else.
Interestingly in the same report the Monash University Accident Research centre(MUARC) openly admits to its research being substantially funded by the RTA and Federal Office of Road Safety (FORS). Independent research I hear you ask????????