The mother of a man killed by a drug driver believes her son would have wanted her to speak up about the issue.

Public consultation has begun on whether the Government should implement roadside drug testing.

Karen Dow's son, 23-year-old Matthew Dow, was killed on New Years Eve 2017, by a driver high on meth and cannabis.

She says until she lost him, she was unaware of how bad the issue is.

"They year Matthew was killed, he was the 79th person killed by a drugged driver. We need to do whatever we can to save any other family from going through the grief that we live with."

Dow says Matthew had an immense sense of justice and as a family, if they can push to prevent any more deaths like his - they need to do it.

She hopes the Government follows up the action.

"Whether this legislation had been passed, whether it would have saved our son, I don't know, but we need to do whatever we can to get drugged drivers off the road."

Dow says this is the correct action to take to protect Kiwis from the "menace" of drug driving.

Last year, 71 people were killed in crashes involving a driver on drugs or medication.