Amid some concerns about the holding-back of traffic such a distance from the location, he said: "It can be difficult to balance convenience of the public with the need to ensure contractors and emergency services staff can quickly and safely reopen the road for everyone. Ensuring the safety of road users, emergency services workers and our contractors is the highest priority."
Emergency services and contractors had a right to be able to undertake their work safely "without the added complications that come from the traveling public trying to get past the accident site," he said.
If staff had sufficient evidence that a motorist lived within the closure area they could allow them through at their discretion, but on Thursday night there were "examples of people who were dishonest about their destination and were let through, then attempting to continue through the crash site," he said.
The closure points were "fully crewed", ensuring no delay in reopening once the road was cleared, he said.
If queues had been allowed to form from the crash site they would have stretched for kilometres in both directions, he said, and would normally impacts on recovery vehicles being able to get to the crash site, past queues of traffic.
"Given the length of the closure, motorists could have been sitting in the queue for more than five hours, as darkness fell, without access to toilets or food and drink," he said.
Highway safety campaigner and truck driver Axel Alexander described the closure as "unnecessary" and "complete bollocks."
He believed two lanes had been open within 30 minutes and salvage contractors would have been able to work around the traffic and would only a short closure for the final movement of getting the truck out.
"I believe wholeheartedly that more electronic signs are needed to inform people where the closure is and allow them to make up their own minds," he said.
"The only sign is at Napier airport and a single word sign at Taupo that informs whether the road is open or closed," he said. "Not sufficient. The road could have remained open for traffic under a stop-go, pure and simple."
