Mr Woodhouse said: "I haven't ruled that out, but it is going to be difficult. What I have said to Sean is what we will do ... is have a look at every idea we can to ensure that those drivers are not at greater risk than we are."
The issue of tourist crashes has returned to the spotlight following two fatal crashes involving foreign drivers earlier this month.
Mr Woodhouse said tourists were not at a greater risk of car crashes than New Zealanders. But in the lower South Island, tourists were involved in a far greater rate of crashes.
Police estimated foreign motorists were involved in around 25 per cent of crashes in the central and lower South Island, compared to 2 per cent nationwide.
This problem prompted the Visiting Drivers programme, which was launched last month. The programme, led by the New Zealand Transport Agency, would research why drivers from outside Queenstown, or from overseas, were having difficulty on the roads.
Mr Woodhouse told delegates about New Zealand's falling road toll, but said more work was needed.
The minister believed technological advances such as self-driving cars and adaptive cruise control could allow government to set a goal of a "zero road toll" within his lifetime.
"These things are already in. The question is how do we introduce them into the market so that people will drive the safest cars they can afford?"