Government will introduce a "one-strike" policy for suspected drink-drivers who evade prosecution because medical staff cannot extract a blood sample.
Around 20 people exploit a legal loophole each year by using their right to refuse a breath test, before escaping punishment because they cannot give a blood sample for medical or physical reasons.
They were typically heavy drug users whose veins were too damaged for medical staff to extract blood.
As part of a law change to lower the maximum drinking limits for adult drivers, Government will attempt to close this loophole.
Any driver who knew they could not give blood would only get one chance to refuse a breath test. If they refused after being pulled over by police a second time, they would be prosecuted.
"The presumption is that the driver, having foreknowledge of that probable outcome, had in effect refused the blood test," the bill said.
Cracking down on this small group of drivers has proved complicated.
Police were exploring alternatives for taking blood samples, including specialised equipment.
Under the reforms, drivers with a blood-alcohol content of 50mg to 80mg of alcohol per 100ml of blood would be fined $200 and 50 demerit points. If they refused a breath test and a blood sample contained between 50mg and 80mg of alcohol, their fine would be increased to $500.
*Maximum blood-alcohol limit lowered from 80mg to 50mg of alcohol per 100ml of blood.
*Maximum breath-alcohol limit lowered from 400mcg per litre of breath to 250mcg per litre.
*Drivers caught between the new and the old limit fined $200 and 50 demerit points.
*Drivers who refuse a breath test and are found to be intoxicated have their fine raised to $500.
*Drivers who twice refuse a breath test and cannot produce a blood sample can be prosecuted.
*Extended police powers to immobilise vehicles or forbid people for driving for 12 hours.