Parents right across the country were shocked by the deaths of four young children who were hit by a car as they were walking beside the road in the Sydney suburb of Oatlands three weeks ago.

Police allege that the driver in that tragic incident had been drinking for much of the day and had a blood alcohol reading three times the legal limit.

The crash and its appalling toll naturally sparked a new round of discussions on road safety and, particularly, the question of whether the legal limit for drivers should be lowered to 0.0, a position supported in the metropolitan press over the weekend by the father of three of the young children killed at Oatlands.

So, could it ever happen?

Perhaps the first question to be asked is how many crashes involve drivers who test positively to alcohol in their system but come in below the 0.05 legal limit.

Quite likely, it's not many.

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And so the strongest argument to push for a zero alcohol limit might not be that it takes away the grey area for drivers by putting an end to the situation where drivers might think they're fine to drive only to find out (too late) that they were more affected than they thought.

And nor should we expect a zero alcohol limit to stop those drivers who have been most affected by alcohol from getting behind the wheel. Sadly, people who have had too much to drink will continue to make bad - potentially catastrophic - decisions.

But what a zero alcohol limit might do is help change a culture of casual drinking in this country that allows people to think that just a couple of beers before driving won't hurt.

A zero alcohol limit might make Australians think more seriously about the prominence of drinking in our society and make us question if we have the balance right.

That would not be easy, however, and we may be confronted with issues we're not yet ready to face as a nation.

But 40 years after the introduction of random breath testing, alcohol remains one of the big four killers on our roads.

The road toll is lower now than it was back then, but still we can do better. Maybe it's again time for a new approach.