An international road safety expert says the Government must keep applying targets to reduce road fatalities and serious injuries - and that reversing speed limit reductions will drive the road toll up.

It comes as officials are working on a new safety policy after the Road to Zero was scrapped.

Eric Howard is convinced the road toll will climb if speed limit reductions stop, and if lower limits are reversed across the country.

Eric was manager of road safety for VicRoads in Australia when the state reduced deaths by 20 per cent.

He's since provided advice on safety in over 30 countries - and has done so for Auckland Transport.

"Anybody who's prepared to put an hour's work into reading some of the literature and the research evidence, and practical evidence in case studies in this part of the world - would say why are we doing that, that's going to put the level of deaths and serious injuries up, unequivocally."

Eric backs vision zero strategies - which aim for zero deaths on road.

The previous Government's $2.9 billion Road to Zero aims to cut deaths and serious injuries by 40 per cent by 2030 through safety upgrades and lower speeds.

It also aims for zero deaths or serious injuries by 2050.

Ministry of Transport officials are now working on a new safety strategy.

A spokesperson says no decisions have been made on whether any new targets to reduce road deaths will be included in the policy.

Eric says that's concerning.

"If you don't have an idea where you're headed, it's unlikely that you'll arrive. It is important to have targets and it's important to be accountable for those targets."

The Road to Zero came under criticism for not making progress quickly enough - the road toll shot from 318 in 2020 and 2021 to 372 in 2022 and 341 in 2023.

A Waka Kotahi spokesperson says it had reduced road deaths by 10 per cent and serious injuries by 7 per cent by 2024.

Around $1.9 billion was spent on the policy by 2024, and 225 kilometres of median barriers were installed by then.

A 2023 report identified that 1000 kilometres of median barriers needed to be installed to reach Road to Zero targets.

Plans to reduce speeds on a further 1 per cent of the most dangerous roads were predicted to avoid 60 lives or serious injuries. That was also halted late last year.

Transporting New Zealand chief executive Dom Kalasih says the Road to Zero was nothing more than a marketing ploy.

He is expecting a more analytical approach to safety initiatives from the new government.

"By that I mean, things like benefit costs and whether investing in a road safety initiative is going to get return, those sorts of things will change, and I think that's a very good thing."

Auckland Transport brought in lower speeds on 800 kilometres of road across the region in 2020.

An interim report from AT found there were 30 per cent fewer deaths on roads with the lowered limits.

Road safety manager Ping Sim says she's waiting to see whether old speed limits will return.

"What we found in Auckland's roads, is that we did see a significant drop in deaths in roads where we had changed the speed limits."

Eric says in Melbourne, streets that lowered speeds from 40 to 30 km/h showed serious injuries for pedestrians decreased by 71 per cent, and by 49 per cent for cyclists over four years.

Eric says people should watch changes in safety closely.

"I think it's an issue for discussion with the New Zealand community.

"What do you think about what's being proposed, what do you think about the measures being taken to reduce death and serious injury, or are you not interested in whether people are killed or not?"

"It could be you, it could be your family, it could be your friends, but the fact of the matter is, the level of death is not coming down."

The Minister of Transport Simeon Brown says in a statement that safety is critically important to him and that police officers will be required to roll out 50,000 roadside drug tests per year and three million alcohol breath tests per year.

The Government's new safety strategy will be released later in the year, as will changes to speed limit rules.

- RNZ/ Ellen O'Dwyer