Husband John Fairweather has urged those responsible to "man up" and hand themselves in.
"You've given us a life sentence. Hope you're bloody proud of yourselves," he said on Radio New Zealand.
"If it's a prank and a joke, it's cost a lot of people grief, and we're devastated. I'll never be the same again."
Mrs Fairweather had been out to babysit her grandchildren in Kaponga and was returning home when the incident happened.
"The last I said to her was be careful. The last thing my daughter said to her on her way home was be careful."
Mrs Fairweather had reached Normanby when she came across the barriers.
"She got out of the car, trying to save other people's lives, went to remove it and got struck. It was just her being nice. She was like that, trying to help some poor family that might have run into it," Mr Fairweather told Radio New Zealand.
"I don't know how she didn't see or hear anything coming, but that's how it happened. She just got hit, and unfortunately it was the biggest mistake she ever made.
"I'm gutted. I've lost the love of my life."
The driver who struck Mrs Fairweather had a first aid certificate and tried to resuscitate her, but was unable to.
Mr Fairweather said his wife would have no animosity towards the driver: "He tried to save her."
Mrs Fairweather was always helping others and was well-loved by family and the community. She volunteered at the local hospice shop and looked after friends and family.
"She was a diamond - you wouldn't have found a more generous lady in your life."
Police were seeking witnesses who may have seen the barriers being moved from the footpath onto the road.
Detective Guy Jackson of Taranaki CIB told Radio New Zealand that pedestrians had been seen in the area and there may have been a party nearby.
Police were keeping an open mind as to what had happened.
Mr Jackson said it was a "stupid act" with a tragic outcome. He hoped whoever was responsible would come forward and let the family get on with their grieving.
Anyone with information was asked to call Mr Jackson on (06) 215 5263 or the anonymous Crimestoppers line on 0800 555 111.