This question comes in response to an article that appeared in The Leader; Zoe Powell and Knox Leader ‘The Basin CFA slams ‘clown show’ drivers at serious Kilsyth car accident‘ (March 28, 2017). I am asked:
What are the legal requirements for road blocks and following instructions if an agency other than Police are controlling the scene and traffic?
In Victoria, the Chief Officer of the CFA ‘may close any road or part of any road affected, or likely to be affected, by a fire or smoke from a fire and may direct traffic on any road in the vicinity of the closed road (or closed part of a road)’ (Country Fire Authority Act 1958 (Vic) s 30(f)). That is related to fire and is part of a section headed ‘Powers of officers at fires’ (see also s 44A).
The CFA is also authorised to provide road rescue services (s 97B). By virtue of s 97D:
The powers and immunities conferred by this Act on the Chief Officer extend and apply to the Authority with such modifications and extensions as are necessary to enable the Authority to perform its functions under section 97, 97A, 97B and 97C and the provisions of this Act apply with such adaptations and variations as are necessary to and in relation to the performance of those functions to the same extent as in the case of the prevention and suppression of fire or the protection of life and property in the case of fire.
So just as the CFA has the power to close a road to allow them to deal with fire, so too they have the power to close the road as part of their road rescue functions.
There is however no provision that says it is an offence to fail to comply with a direction by the CFA, so although they may close the road, a driver commits no offence if they ignore the road block.
There is an offence of driving so as to interfere with the brigade, s 107(4) says:
A person must not, without reasonable excuse, drive a vehicle within such proximity to the place of a fire or to any apparatus in use at a fire as to interfere with—
(a) the operations of any brigade, group of brigades, interstate fire brigade or international fire brigade; or
(b) the use of the apparatus.
Penalty: 60 penalty units.
(In Victoria, a penalty unit is$155.46 (see Justice and Regulation, Penalty Units, 2 February 2017) so the maximum fine is $9327.60).
Again section 107(4) relates to operations at a fire, but by virtue of s 97D it would be argued that these provisions extend to apply to the scene of a road rescue so that driving so as to interfere with brigade operations at a rescue is also an offence.
Australian Emergency Law 
Would the same/ similar apply to SES volunteers who close a road at a road rescue incident? or where a tree is blocking the road?
The Victoria State Emergency Service Act 2005 (Vic) s 40 defines a ‘traffic emergency’ as:
At a traffic emergency, where ‘the most senior of the authorised emergency workers is of the opinion that it is necessary to direct traffic in the area’ or ‘the most senior police officer in attendance … is of the opinion that there are insufficient police officers in attendance to safely direct traffic and the assistance of authorised emergency workers is required’ then a member of the State Emergency Service who has completed the necessary training may ‘give reasonable traffic directions to the driver of a vehicle within the immediate area of the traffic emergency.’ It is an offence for a driver to fail to comply with a direction given under these circumstances. The maximum penalty is a fine of 5 penalty units (ie 5 x $155.46 = $777.30).