Driving offences on either side of the border are again in conflict with New South Wales moving to take what it describes as a "commonsense" approach and revise conditions around its 40km/h speed limit near emergency vehicles.
However, ACT has refused to budge on the new law, which it introduced in mid-April last year and for which it has issued 10 fines and 41 cautions.
ACT Minister for Road Safety Shane Rattenbury believes that "people can see the flashing lights [of emergency vehicles] and have plenty of time to slow down" and that feedback in the ACT has been "positive".
But the minister's view runs contrary to the key findings of an academic evaluation of the NSW trial, in which "some people interviewed suggested that the requirement for drivers to slow down to 40km/h was potentially dangerous in some situations".
As a result of the evaluation, in NSW from September 26 drivers will only be required to slow down to 40km/h when passing stationary emergency vehicles where speed limits are less than 90km/h.
On highways and arterial roads, the NSW measure is that motorists "will be required to slow down safely to a speed that is reasonable for the circumstances".
This avoids the significant issue identified by the evaluation where motorists brake suddenly from high speed when they see emergency lights, only to potentially cause another incident.
The NSW evaluation also expanded the definition of emergency vehicles to include tow truck drivers and breakdown assistance providers, such as NRMA roadside support vehicles, "as well as the people they are helping".
"Motorists must also provide sufficient space between their vehicle and the stationary tow truck, breakdown assistance or emergency vehicle displaying flashing lights," the rules states.
"This will include changing lanes on a multi-lane road, if it is safe to do so".
In the ACT, motorists potentially face a $257 fine and incurring two demerit points, regardless of the speed limit.
ACT police and emergency services have been supportive of the new road rule but there has been no formal evaluation completed here, as it has in NSW.
The ACT rule also does not extend to tow trucks and breakdown assistance vehicles
The issue has been a conflicting one for motorist advocacy group NRMA, which has been caught between supporting its membership critical of the practical application of the new rule, and support for its breakdown assistance operators.
In May 2012, NRMA tow truck contractor Geoffrey Clark and 23-year old Sarah Frazer were both killed in the breakdown lane of the Hume Highway.
Sarah, an NRMA member, was driving to Wagga Wagga to begin university when her car broke down in the Southern Highlands near Mittagong.
Mr Clarke was hooking up her car to his tow truck when both pedestrians were sideswiped by a truck approaching from behind.
The tragic incident led to the creation by Sarah's father, Peter, of the National Road Safety Week, which campaigns for improvements in road infrastructure, vehicles, regulation and driver behaviour.