New report: Slower SH5 speeds prevent 34 crashes in 12 months

A new report has found lower speeds imposed on SH5 Napier-Taupō road has reduced crashes. Photo / NZME

An independent report of the policy that has seen the Napier-Taupō highway’s 100km/h speed limit reduced to 80km/h has found it prevented 34 crashes in 12 months.

The report reckoned the lower speed limit added 0.5 to 2.8 seconds per km travelled, increasing journey times of between 36 seconds and 3.6 minutes across a single journey.

A cost-benefit model reckons the avoided crashes created $93 million worth of benefits, while the slower journey times created costs worth $1.3m that year. A sensitivity analysis showed benefits range from $65m to as high as $120m.

The review was conducted by Ernst and Young for Waka Kotahi NZ Transport Agency. It looked at a 76km stretch of State Highway 5 between Rangitāiki and Esk Valley, and took in the period between March 2022 to February 2023.

The issue was earlier raised on Tuesday night at the Hawke’s Bay Today Napier candidates’ meeting.

Asked at the meeting whether returning lower speed limits to 100km/h might lead to more fatalities, National Party Napier candidate Katie Nimon said the question missed from the party policy statement was that it was “also going to upgrade those roads.”

She said speed limits had been lowered in the Labour Party term “because they are unwilling to upgrade them to the higher safety limit”.

“We are going to upgrade them and then we’re going to make sure that those speed limits don’t take our country and our productivity,” she said. “That is really important for us to do that.”

Hawke’s Bay Today on Wednesday asked what plan there would be on lowering speeds and for a safety programme on State Highway 5 (Napier-Taupō), but had been unable to contact Nimon again.

Napier’s Labour candidate, Mark Hutchinson, reiterated late Wednesday afternoon that Prime Minister Chris Hipkins had in March announced a “significant narrowing” in the speed-reduction programme to focus on the most dangerous 1 per cent of state highways, while recently it had announced plans to spend $5.3 billion over the next four years on major projects nationwide, including four-laning of the Hawke’s Bay Expressway.

National has also announced similar intentions relating to the Expressway.

There had been 16 fatalities and 250 injuries since 2010, including nine deaths from crashes on the highway in the 20 months from February 2019 to October 2020, all but one of them in the sector in which the speed limit was reduced.

But, amid greater vigilance on SH5 from police in both the Eastern and Bay of Plenty police districts and a “Stay Alive on 5″ signage campaign, no more had been recorded in the two years since the lower limit was imposed.

There have been three fatalities this year, two in a single crash in a 100km/h zone near Iwitahi (about 23km from Taupō) and one in the 80km/h zone between Eskdale and Te Pohue.

Hastings District Council Deputy Mayor Tania Kerr says the independent Waka Kotahi analysis relating to SH5 found there have been safety and economic improvements since the lowering of the speed limit on SH5, but as Waka Kotahi acknowledged, it was only a year’s worth of data, and a more detailed analysis over a longer timeframe is needed to determine whether a lower speed limit has been the most effective means to deliver improvements.

“Through local working groups, our council representatives have been focused on ensuring our communities’ views on SH5 were clearly heard by Waka Kotahi,” Kerr said.

The groups include other councils, community leaders, the Regional Transport Committee, Port of Napier, mana whenua and agencies such as the Automobile Association.

She said ideas have been put forward including shorter-term safety improvements, such as shoulder widening, wide centre lines, side barriers and rumble strips, as well as longer-term safety and resilience works.

“We have advocated strongly for these safety and resilience improvements throughout this process, regardless of the speed limit,” she said. “This route is critical for Hawke’s Bay freight, tourism and primary producers and the community who live alongside it.”