A price to pay for wanting to go faster

A price to pay for wanting to go faster

The Kāpiti expressway between Ōtaki and Raumati South now has a new 110km/h speed limit. 

This will “help to reduce travel times, increase efficiency, and get people and freight where they want to go quickly and safely”, according to Transport Minister Simeon Brown. Local National MP Tim Costley adds that a more efficient transport network means local businesses can be more productive.

We shouldn’t get too swept up in the political hype; many things might improve the productivity of my business in Ōtaki, but being able to drive down to Paraparaumu 62 seconds faster isn’t one of them. And people consistently overestimate the time saved by increased expressway speeds. 

Additionally, the speed limit of 90km/h for trucks set under Land Transport (Road User) Rule 2004 will still apply, so the travel times for freight will remain the same.

Nevertheless, the higher 110km/h speed limit had overwhelming support, with 93 percent of more than 3000 public submissions in favour. In our modern society, with life’s time demands pressuring us to maximise every minute, a high value is placed on mobility and being able to get places quickly – time is money.

The speed limit change is part of the National government’s “Accelerate NZ” commitment to reverse the previous Labour government’s speed limit restrictions. But those speed restrictions were consistent with the internationally recognised Safe Systems approach, which is based on the premise that people inevitably make mistakes, and when those mistakes occur the design of our roads and vehicles, and the speed limits we set, should make the resultant accidents survivable.

Reducing speed is a key Safe Systems tool. The basic laws of physics are clear: the faster you go the more accidents you will have, and the more serious those accidents will be.  Even on the well-designed German autobahns, every year thousands of people are seriously injured, and hundreds die. There are injuries and deaths that largely would have been avoided if people had been driving slower.

Under the Safe Systems approach, in residential areas where there is a high risk of interaction with pedestrians, vehicle speeds should be 30km/h – if a pedestrian is hit by a car at 30km/h there is a 90 percent chance they will survive, but only a 20 percent chance at 50km/h.

Slowing drivers in residential areas is also more equitable; drivers shouldn’t have all the benefit of being able to travel across town faster while passing all the cost of injury onto vulnerable others (pedestrians, school children and cyclists). 

After the implementation of the Safe Systems speed restrictions in June 2020, Auckland Transport reported a 47 percent reduction in road deaths, and a 25 percent reduction in injury crashes in those speed restriction areas.

Public health academics and other experts, both in New Zealand and overseas, have criticised the reversal of the Safe Systems implementation, pointing out that increasing road speeds not only increases the road toll, but it has the additional costs of increasing fuel consumption and increasing environmental pollution.

Modern vehicles are, by design, most efficient around 70-80km/h (the lowest revs in the highest gear).  These numbers generally hold true regardless of the vehicle make or model, or type (petrol, diesel, hybrid). Increasing speeds beyond 70-80km/h increases fuel consumption (by about 10 percent going from 100 to 110km/h) and increases greenhouse gas CO2 emissions and pollutants like nitrogen oxides – this is the price we pay for wanting to go faster.

A recent study found that lowering speeds on New Zealand roads from 100 to 80km/h had reduced fuel use by about 15 percent. Fuel consumption and environmental impacts are increasingly being taken into account overseas; for example, in 2019 the Dutch government reduced motorway speeds back to 100km/h, primarily to reduce vehicle nitrogen oxide emissions. 

At the individual level these effects can appear minor, but at the societal level they are substantial. In New Zealand the social costs from vehicle pollution (asthma and other respiratory illnesses, cardiac illness, premature deaths, lost productivity, etc) are estimated to be more than $10 billion annually. The social cost of vehicle crashes is another $10 billion, for a combined total of 5 percent of our GDP.  Meanwhile the National government tells us we can be more efficient and productive by going faster! Recent European studies show that driving slower is not only safer but, overall, economically prudent for society as well.

 And, at a time when we are not on track to meeting our climate change obligations, we should be driving to conserve fuel and reduce emissions as transport accounts for 40 percent of New Zealand’s greenhouse gas CO2 emissions. People will argue that their individual contribution would make little difference, so why bother – and that’s why we have a climate change crisis.

The value we place on mobility, human life, the environment, and even which political parties we vote for, is captured and reflected in our road speed signs.