When people are driving, they must take on board the responsibility that goes with it, he said.
"Drivers must be responsible by giving the roads their full attention, driving to the conditions, not driving drunk, drugged, or fatigued and ensuring the use of seatbelts.
"The reality is that seatbelts save lives, being properly restrained reduces your chance of death or serious injury in a crash by 60 per cent in the front seat and 44 per cent in the back seat."
Greally said speed was always a crucial factor in determining the severity of a crash, and injuries to those involved.
"The simple and inescapable truth is that less speed means less harm in a crash."
NZ Transport Agency General Manager of Safety, Health and Environment Greg Lazzaro echoed Greally's concerns.
"It is a terrible fact that on average seven people die and more than 50 are reported seriously injured every week on New Zealand's roads," he said.
Lazzaro said each death, as well as serious injuries, had a "devastating and ongoing" impact on families and communities.
The social cost was also substantial - costing Kiwis $84 million per week, or nearly $4.7 billion a year.
"We encourage drivers to buckle up, drive sober and keep their speeds down, but we also recognise that human beings are fallible.
"We all make mistakes, but simple mistakes should not result in death or serious injury," he said.
"That's why we're working to deliver safety improvements through measures like installation of side and median safety barriers, rumble strips, shoulder widening, better signage, level crossings and speed management."
Greally's call follows a horrific month of April, in which 45 people died in road crashes.
The last time 45 people died in a single month was April 2009.
