The Transport Minister is revealing more about roadside drug-testing as the Government looks to pass the legislation

It's part of a 1.3 billion dollar crackdown on drink and drug driving over three years.

Simeon Brown is hoping 3.3 million breath tests will be conducted a year, along with 50-thousand oral drug-screens when it comes into place.

He says drug tests won't be used as evidence in the first instance.

Instead, Brown says two screening tests will have to come back positive, before an evidential test is taken.