Police say it is a tragedy so many lives have been lost on the roads during the holiday weekend.
The Labour Weekend road toll stands at seven on Monday night, despite a major police operation.
In the latest death, a 16-year-old girl was killed when a vehicle crashed about 11pm on Sunday on State Highway 67, north of Westport.
Four other people died on Sunday, one on Saturday and one on Friday.
National road policing manager Superintendent Paula Rose says she is saddened by the deaths, as they were all preventable.
"Speed, alcohol and failing to keep left - the very things we've been targeting have been behind those crashes."
However, Ms Rose says she is pleased that reports of crashes and unsafe driving are down about 30%.
Police have ticketed any motorist caught doing more than 4km over the speed limit.
The holiday period runs from 4pm on Friday until 6am on Tuesday.
Eight people died on the roads during Labour Weekend last year.