New Zealand drivers are encouraged to select cars with a four or five star safety rating over lower rated vehicles. But are we selling ourselves short with the current five-star scale?
Many of our rated five star vehicles are not truly five stars when it comes to road safety. People are still killed and seriously injured in car crashes involving four- and five-star vehicles, especially when those vehicles are driven at high speed or where there is a large mass (weight) difference between vehicles involved in crashes.
The current star rating system also mainly focuses on the safety of the vehicle’s occupants and the risk to them of death or serious injury. While vulnerable road user risk (pedestrians and cyclists) is considered in the assessments, it only directly makes up 20% of the overall score. The risk a larger vehicle poses on occupants of existing smaller vehicles is also not considered directly. While driver assist vehicle technology is now considered in the assessment (at 20%) there are concerns with the safety effectiveness of the ‘affordable’ advanced driver assist system (ADAS) technologies.
The highest, five-star vehicle rating should only be given to vehicles when the risk of death or serious injury in a crash is extremely low for all road users.
To qualify for five stars, our cars should not only be built safer, but they should also be smarter, with proven technology. Many larger vehicles that have been given a five-star status, such as utes or large SUVs, pose a greater risk to occupants of smaller vehicles on the road and more vulnerable road users, such as pedestrians, cyclists or motorcyclists.
A five-star vehicle rating should be an aspirational goal. A five star vehicle should have an extremely small chance of causing death or serious injury to any road user – inside or outside the vehicle. If all vehicles had this status, then we would be well on our way towards achieving zero deaths and serious injuries.
So, how can we make our vehicles safer?
A good starting point is to use technology to prevent these tragic crashes. Some modern five-star vehicles do have driver assist technology (like emergency braking) and pedestrian detection systems, but many of these systems do have their limitations, especially when driving in busy urban traffic. For example pedestrian detections systems do not work when vehicle is turning.
While the technology exists, only some modern vehicles are equipped with intelligent speed assistance (ISA), which helps keep vehicle speeds below the speed limit, by alerting the driver or by automatically reducing the speed. Even when this technology is available it is often just a warning system, rather than actively managing vehicle speeds, and experience overseas is that many drivers do turn off warning systems. So even if emergency braking and pedestrian detection is enabled, the vehicle may not be able to stop in time to avoid severely hitting a vulnerable road user or occupant of a lower mass vehicle if driven at inappropriate speeds – even if these speeds are within speed limits.
Other countries are more advanced in mandating ISA and driver assist technologies in new cars. The European Commission mandated a range of safety features for all new vehicles (which will soon apply to all cars sold after May 2024) and has identified other features that will be required over the next six years. We need to do better in New Zealand and introduce stronger legislation around ADAS to improve the safety of our vehicle fleet. This is particularly important in New Zealand given the old age of our vehicle fleet and the delayed time in fully benefiting from new vehicle technology.
While this may be considered too expensive, or impractical, I would ask, what is the cost of a life?
Shane Turner
Technical Director, Road Safety