A total of 46 serious crashes have been alcohol-related between 2016 and 2020 with poor observation the next most significant factor, contributing to 32 incidents.
Ashburton Ward councillor Diane Rawlinson said the numbers left her shocked.
"I was actually quite shocked that alcohol was way out in front," she said.
"I've got an 18 year old grandson and their wider group of semi rural kids, who do a lot of driving but they look out for each other and someone is always the safe driver.
"I probably dumbly assumed that all groups of young people do that."
The road safety action plan 2020-21 report stated that drivers aged between 20-29 remain as the dominant age group (39 per cent) contributing to alcohol related crashes.
Road safety and alcohol ave been tackled previously through campaigns run through the Ashburton Community Alcohol and Drug Service (ACADS) including the Community Alcohol Action Plan and the Driving Whilst Impaired programme.
Rawlinson also suggested that people were also lacking vigilance behind the wheel.
"Stupidity is never going to bring the statistics down" she said.
"It's always going to add to it."
Council's road safety strategy for the next ten years aims to reduce death and serious injuries on Ashburton roads by 40 per cent.
"In reality, I don't think we'll ever get back to zero simply because of the way people drive."
One in three death and serious injury (DSI) crashes have occurred at an intersection.
Drivers contributed to intersection crashes are divide evenly between male (56 per cent) and females (44 per cent)
Drivers aged between 16-29 represented as a high risk age group for DSI crashes (37 per cent).
"Also, there has been a surge in crashes for drivers aged between 65-69.
"The most common movement category for young drivers are losing control on straight roads and on bends," the report said.
There have been a total of 8 deaths from 4 crashes this year compared to 3 deaths recorded in 2020.
