The grandmother of five children who died alongside their parents in a horrific crash at Atiamuri says "no words can fully describe the agony" of the whānau's grief.

Sherilyn Poutawa said the tragedy of losing seven loved ones had been a devastating shock.

"Our whānau were on their way home, not far from here," she told reporters at Waikato Hospital today.

She had been waiting at home with another grandson, she said.

The sole survivor of the crash, 9-year-old Legacy, was recovering after a midnight surgery that was successful, she said.

"He's been in surgery, a midnight surgery, and it's been very successful. So he is on a speedy recovery but it's a long journey for him."

She said they're now waiting to return back to home in Hawke's Bay.

The two surviving grandsons were surrounded by a "very big loving family".

Margaret 'Margs' Luke and her children.

• Parents, five kids amongst victims of Taupō crash

"We would like to thank whānau, friends, all work colleagues of my son, school teachers, friends, neighbours for all their condolences and their heartfelt aroha, prayers, thoughts."

The family asked for privacy in the coming days, she said.

"Please continue to pray."

Mourning the loss would be a long journey, she said.

A neighbour of the family in Tokoroa, Ivan Meyers, 89, was distraught at learning the family had died.

He described them as "very nice people and those kids too, were so polite, always a hello".

"They came here and I said 'seven kids, they will be noisy', but you couldn't get better behaved kids.

Dave Poutawa with 7 of his children.

"They were good friends, nice people."

He had also just arranged for the 9-year-old boy to do his lawns so he could get some pocket money.

Colin Arnold, has lived in his Tokoroa home for 21 years, and described the family as "very caring".

The family's vehicle and another being driven by long-serving Scouts employee Jenny Rodgers collided head-on on a sweeping left-hand bend near Ohakuri Rd about 10.30am on Sunday.

Jenny Rodgers was Scouts NZ general manager for lower North Island/National schools. She was the sole occupant of the southbound SUV who also died in the crash. Photo / File

Rodgers was travelling from Hamilton to Taupō after attending a closing dinner at the National Caving School in Waitomo the night before. She has been remembered for her dedication and enthusiasm for the Scouting movement.

Safety issues at crash site

The NZ Transport Agency has found that the stretch of road where the eight people died has several safety issues.

NZTA safety and environment director Harry Wilson said changes throughout the area would "improve safety, and reduce deaths and serious injuries".

"Between 2008 and 2017, 30 people died and 86 were seriously injured on this stretch of road," Wilson said.

"Crash analysis shows common contributing factors to crashes include loss of control, failure to keep left and fatigue.

"Police are investigating the circumstances of the crash and the Transport Agency will be carrying out a thorough review of the road and roadsides at this location."

NZTA is working to deliver the Safe Network Programme, a $1.4 billion investment over three years which aims to prevent 160 deaths and serious injuries.

Wilson said several improvements will be rolled out after the Government made improving road safety a top priority.

Safety measures include installation of side and median barriers, rumble strips, shoulder widening, better signage and speed management.