The reduction in serious and fatal crashes involving teenage drivers might reflect the raised driving age, from 15 to 16, Mr Koller said. And it was international drivers, not young people, who posed the most danger on the roads.
"People from [other] countries can buy their licences overseas, never having sat in a car. They sit the theory test and they get a [NZ] licence."
In 2008 65 people were killed in road accidents involving teen drivers - compared to 24 last year.
NZTA road safety director Ernst Zollner said the old paper scratch test was well past its use-by date when scrapped in 2009.
"All of the questions, the answers and their exact sequences were well known. It was apparent that many learner licence applicants were memorising the tests and learning by rote rather than actually studying the full road code."
The early days of computer testing saw an expected drop in the pass rate, which had steadily increased since then.
"Young drivers have got the message that they really need to learn the road code before sitting the test ... That's great news for everyone who uses the road, because we need our newest drivers to be safe drivers who understand the road rules."
While the reduction in fatal and serious injury crashes involving teen drivers was encouraging, road crashes were still the biggest killer of teenagers nationwide, Mr Zollner said.
In recent years one teenager was killed on our roads every week - one of the worst rates in the developed world.
Last year the NZTA introduced a tougher practical test for restricted licence applicants. Other changes included raising the minimum driving age to 16 and lowering the youth alcohol limit to zero.