The highest crash factor last year was poor handling, which accounted for 35 per cent of all fatal and serious crashes.
The second highest factor was poor observation at 29 per cent of all crashes and the third highest crash factor was travelling too fast for the conditions at 22 per cent.
New Zealand Transport Agency Bay of Plenty highways manager Niclas Johansson said that during the past year they had been working on several safety projects in the region, including installing safety barriers, widening sections of highway and installing new electronic curve warning signage to slow drivers.
"We have also invested millions into maintaining the highways and carrying out rockfall prevention work throughout the region.
"We are about to start work on the SH5/Hemo Rd roundabout in Rotorua, which will significantly improve safety at this high-risk intersection," Mr Johanson said.
"Later this year we also plan to start work on a $24 million roading package which will focus on Rotorua's eastern and central corridors with an upgrade to State Highway 30/Te Ngae Rd."