Mr Merrill described the accident as "pretty horrific".
"My bones, they were just pulverised," he said.
"One of my teeth was knocked out of my mouth and into my lung. I had to have plastic surgery to my face.
" I looked like somebody had attacked me with an axe. My arm, I had a compound fracture. My arm had to be totally rebuilt. My elbow and forearm. Thankfully, I mentally wasn't there."
Mr Merrill had severe brain trauma for 29 days. Doctors told his family they did all they could but no one knew if he would survive or not.
At one point, his lungs collapsed.
"Thank God ... I lived," Mr Merrill said.
"The first time I even realised I was alive was 73 days into it. I was in brain rehab in Auckland. They had to tell me 'you've had a very bad accident. Your name is Ed.'
"My wife had to say to me 'I'm your wife. My name is Mary.' Apparently I called her 'wife' for two weeks."
Mr Merrill said the brain injury forced him to relearn simple things again "like brushing my teeth".
"The neurologists, there were three, they all said I was lucky but the third one said 'you are in the top 1 per cent of lucky'," he said.
"Ninety-seven per cent of brain hurt people could not speak but I could.
"I would try to talk to employees up there [at rehab] and some of them would scream."
Mr Merrill said he still had cracked or broken brain neurons, which mean it was harder for him to do day-to-day activity and he became easily tired.
But his recovery has brought him back to nearly the point he was before the crash.
The first time I even realised I was alive was 73 days into it. I was in brain rehab in Auckland. They had to tell me 'you've had a very bad accident. Your name is Ed'.
"I will feel it for the rest of my life. I'm so thankful I'm still here."
Mr Merrill's O- blood type is considered particularly special.
"They told me that my blood is the blood they use for babies because it's one of the most rare ones."
It also meant his body can only accept the same rare blood from people who donated.
"I'm very appreciative of what's happened."
Mr Merrill had donated blood just once before his crash.
He is now a regular at the Tauranga Cameron Rd branch of New Zealand Blood Service.
"You never know what's around the corner," he said.
"It's good karma to give blood, in the hope that you and your loved ones never need it. It's just a good thing to do.
"Doing something good for others, it does make you feel better."
On average, blood and blood products are used by 135 Kiwis every day.
NZBS national manager marketing and communications Asuka Burge said that while Tauranga had nearly 5000 donors, it needed at least 30 new blood donors every month to keep up with demand.
"Nationally, every year we lose about 29,000 donors off our database. We would love more New Zealanders to step up and consider becoming somebody's hero."
Who needs blood?
- The need for blood is constant. In
New Zealand, 125,000 whole blood
units will need to be donated in the
next 12 months to meet clinical
needs.
- This blood will be used for cancer
patients
- For those undergoing surgery
- To treat accident and burns
victims
To treat shock
- To provide clotting factors for
people with bleeding disorders,
including haemophilia
- To provide antibody treatment for
people with disorders of the
immune system
- Regular blood donors ensure that
a safe and plentiful supply of blood
is available whenever and wherever
it is needed
- NZ Blood Service