Australia was the first country in the world to introduce oral roadside drug testing.
What started in 2004 in Victoria, is now in full use across every state and territory.
Hundreds of thousands of drivers are tested every year for traces of cannabis, ice and ecstasy.
While drug-testing has been around for more than a decade, in the last 12 months the number of drivers being caught has spiked.
In NSW alone, conviction rates doubled in 2015.
This month Lismore lawyer Steve Bolt was involved in a case that has ignited debate on the fairness and accuracy of roadside drug testing.
A case against one of Steve's clients, Joseph Carrall, was thrown out by a local magistrate who labelled the drug-driving laws as mysterious and uncertain by design.
The magistrate's ruling doesn't set a legal precedent, but it has struck a chord with critics of the roadside drug-testing regime.