A new Automobile Association study has found people on drugs are causing more fatal crashes than those behind the wheel drunk.
In 2017, 79 drivers involved in fatal crashes were found to be under the influence of drugs, compared to only 14 in 2013, Stuff reports.
Seventy drivers were found to be over the alcohol limit or refused to be tested.
The AA says the figures show a need for roadside testing of drivers for drug intoxication, as the current methods are insufficient.
Right now an officer must have strong cause to test for drugs and will then take the driver to a station for a "walk and turn" test.
"The current system almost needs a driver to be sitting in the car with drugs on the seat next to them to get tested, and the current test takes up a huge amount of an officer's time," AA road safety spokesperson Dylan Thomsen told Stuff.
But the Government isn't quite sure about roadside tests, saying there are challenges around implementing the preferred method of saliva testing.
"Solutions to tackle drug driving need to be based on evidence and, ultimately, be effective," Associate Transport Minister Julie Anne Genter said.
"I am aware that there remains a number of practical challenges around saliva testing, including the reliability of the testing technology and the time it takes for police to obtain an accurate result."
National MP Jami-Lee Ross currently has a Member's Bill before Parliament that would allow for roadside saliva testing for meth, ecstasy and cannabis.