Two of New Zealand's leading public health experts are calling for authorities to ditch the one-size-fits-all border control process for a risk-based approach.
The system would help facilitate travel from places free of Covid-19 while reducing the risk connected to people arriving from places with an uncontrolled spread.
The University of Otago's Associate Professor Nick Wilson and Professor Michael Baker have dubbed it the traffic-light system.
However, when speaking to the Herald this morning, Baker says he wouldn't emphasise the details "too much" at this stage.
"I think you need some way of tracking people whatever system you use," he says.
"I think there will be some concern about quarantine-free travel for a period, but I wouldn't worry too much about those details yet.
"Fundamentally, right at the centre of [the traffic-light system] is moving away from a one-size-fits-all to a risk-based system."
Green lights
Most Australian states and some Pacific Islands would be granted green lights, given their elimination of the virus.
Baker says given the low levels of transmission in New South Wales, it wouldn't get a green light. Victoria needs a longer period without transmission too, he says.
Jurisdictions would need to be able to prove elimination requirements are being met to New Zealand's standards, such as adequate levels of testing.
Amber lights
Japan, South Korea, and Singapore are jurisdictions where there is evidence of ongoing virus spread but where it is relatively well controlled.
The current border quarantine measures would remain in place for amber zones, however, their facility-based stays would be shortened and replaced with home quarantine.
The isolation period at home would be combined with the usual testing regimes, with digital tracking, mask use and heavy fines for any breaches, according to The Conversation.
A bond would help ensure people are adhering to the conditions of their isolation.
Red lights
Red lights would be given to countries like the United States, United Kingdom, and Russia where there the virus spreads uncontrolled.
New Zealanders returning from these places could be required to quarantine before leaving their country of origin and also presenting a negative test before flying.
Wilson and Baker say red-light measures require careful development, but authorities should evaluate measures being used overseas, such as pre-travel testing.
How would the system help?
Baker says the traffic-light system would help in two key areas: reducing the risk of border failures and increasing the capacity of MIQ facilities.
Allowing people from green-light zones to travel directly into New Zealand helps ease the strain on our MIQ facilities and staff.
"It reduces the risk of border failures because, if you like, you're turning down the tap which is the source of cases," Baker says.
"That's people coming from high-risk countries who are getting on planes and their level of risk is pretty much reflective of what is happening in their source country.
"As we progress to quarantine-free travel, you would divert a lot of people away from the MIQ facilities … You're solving two problems quite quickly by doing this."
Baker says hotels are not designed to be MIQ facilities and there are still questions about how the virus spreads, as ventilation is a key issue.
"The finger has been pointed at lift buttons and rubbish bin lids but really, in most of those cases you can't distinguish between fomite (touching a surface) and an aerosol," he says.
"They are things that would be fixed in a purpose-built facility … One of the benefits it provides is a facility that could be used for future pandemics as well.
"It's a huge decision to work through, but given the increasing risks for pandemics of various scales, we think it would be maybe a strategic asset that should be looked at."
Asked if there should be any major concern among the community, Baker says New Zealand has got pretty good at beating virus outbreaks.
"New Zealand is good at contract tracing and stamping out these outbreaks quickly," he says.
"We can be optimistic and the thing is, other than the Auckland August cluster, the following six border failures have been identified early and managed effectively."
The golden rule is if anyone has any symptoms they should stay home, seek advice and if told to do so, get a test for the virus, Baker says.