The German couple had to be cut from the van but died at the scene. The truck driver also had to be freed by firefighters using cutting gear and was in a serious condition.
Sergeant Dylan Robinson said police had worked with the German consulate to inform the parents of the couple about the tragedy.
Police were continuing to gather information that would be handed over to the coroner.
Ms Picht had documented their travels on a blog called Adventure In My Backpack and had regularly posted to Facebook.
"I have always been drawn into the wide world. On my trip around the world I will conquer the world with lots of chaos, bad word jokes, adventures and Marc in my luggage," Ms Picht said.
She described how nine days before leaving home the anticipation and nervousness was increasing and of how their apartment looked like a battlefield as they packed.
On September 17 last year she posted: "Pure excitement! After two and a half years of planning and saving, we are finally at the airport and start the adventure!"
A post two days later said they had celebrated the start of their "world tour" with tacos in Mexico.
Next on their adventure was Canada, various stops in America including New York, then Rarotonga before landing in "beautiful New Zealand" about November 19.
Ms Picht writes about getting their van and converting it for under $150 so they could camp in it as they travelled.
The South Island appeared to be their first port of call and they had been to iconic landmarks including Mount Cook, Lake Tekapo, Stewart Island and the Abel Tasman National Park.
In their last post on March 8, two days before the fatal crash, they wrote about their walk into Aoraki Mount Cook National Park.
"Mount Cook is the highest mountain in New Zealand, and we couldn't not take a visit to him."
It was unclear how long they had been in Northland.
The cause of the accident would be determined by the police Serious Crash Unit, which examined the scene on Saturday afternoon.
Thirteen people have died on Northland's roads so far this year, compared to eight at the same stage last year.
