How is the safety of a vehicle assessed?

Did you know that not all new vehicles are safety-tested independently? In the UK, the main test centre Thatcham explains: “So many new vehicles are launched each year that it’s not possible to test every one, and certainly not every variant offered by manufacturers.” Instead, they pick the most popular or interesting models, usually as they enter the market.

If a model is already on sale, a test vehicle will be bought anonymously from a dealer. The manufacturer is then informed of the vehicle identification number (VIN) and asked to confirm the spec is up to date. If not, a new part can be added so that it’s representative of current production models. If it’s pre-launch, representatives will visit a car manufacturer’s factory and pick one at random from the production line.

The result is that most, but not all, vehicles have a ‘New Car Assessment Programme (NCAP) safety rating of 0 to 5 stars. Their ratings indicates how well the vehicle is likely to perform in a crash. Vehicles with 4 and 5 stars are the safest.

The first NCAP (which assessed frontal impacts) was created in the US in 1979. There are now at least a dozen NCAP organisations that operate across different regions around the world and they typically take their lead from Euro NCAP.

From 2016, there have been two ratings per car in Europe: a ‘base’ rating out of five that indicates the safety of the car fitted with standard safety equipment and – if the manufacturer wishes – a second, ‘dual’ rating on the same scale. This allows buyers to see the safety options open to them if they pay for additional crash-avoidance equipment.

And, as technology evolves, so does the testing. This means that the year of test is vital for a correct interpretation of a car’s result. The Renault Zoe, for example, scored 0 stars in 2021, whereas it had scored 5 stars in 2013. The decision to remove an airbag affected the score on this occasion.

Panel: Meet the THORs

THOR stands for Test device for Human Occupant Restraint. Other ways to describe it are as an anthropomorphic test device (ATD) and more simply as a ‘crash test dummy’. Both the US and European NCAPs (New Car Assessment Programmes) rely on a THOR’s measurement capabilities. These highly sophisticated and sensitive test devices have been developed to accurately estimate the risk of head, neck, chest and abdominal injury. A THOR-50M represents a 50th percentile male in terms of size, whereas a THOR 5th represents a female on the 5th percentile, so much smaller.

Europe’s safety star-ratings explained

5 stars: Overall excellent performance in crash protection and well-equipped with comprehensive and robust crash-avoidance technology.

4 stars: Overall good performance in crash protection; additional crash avoidance technology may be present.

3 stars: At least average occupant protection but not always equipped with the latest crash-avoidance features.

2 stars: Nominal crash protection but lacking crash-avoidance technology.
1 star: Marginal crash protection and little in the way of crash-avoidance technology.
0 stars: Meets legal minimum standards, but lacks critical modern safety technology.

What is actually tested?

The website Carbuzz lists the main areas covered by safety evaluations and crash-testing procedures in the US, which is broadly similar worldwide:

Frontal-impact tests. Frontal crashes are responsible for more deaths and serious injuries than any other accident type. Frontal-impact crash tests are performed against a barrier to measure the forces on crash-test dummies. There are various test types to determine how a car's structure absorbs an impact when struck from different angles.
Side-impact tests. Side crashes account for the second highest frequency of death and serious injuries. Vehicles are hit from the side by a weighted crash trolley to determine side-impact protection. Plus, as some side impacts involve a vehicle travelling sideways into rigid roadside objects such as trees or poles, this is also tested.
Rollover tests. Taller vehicles, such as SUVs and pickups, are more likely to roll over than passenger cars. According to the IIHS, SUVs have a rollover rate that is two to three times that of passenger cars. In the tests, vehicles are propelled sideways to test their propensity for rolling over.
Roof strength tests. During these tests, a machine crushes the roof structure to determine how much weight is required before it fails. A minimum standard has to be met.
Headrest tests. A car's head restraints are vital for guarding against the whiplash neck injuries that often accompany a rear-end collision. However, many cars' rear restraints are too low to do much good. In the tests, seats are mounted on a rail and a procedure called sled testing is used to determine the headrests' ability to prevent neck injuries.
Headlight tests. Headlights are tested and graded, both the standard-fit headlights and optional ones.
Safety equipment tests. The strength and ease of use of other safety equipment such as child seats and restraints are evaluated.
Driver-assistance features. The performance of driver-assistance features such as automated braking, pedestrian and cyclist detection, and blind-spot warning are evaluated.

Duty of care

When assessing which vehicle to buy for fleets, HSE managers will need to look closely at safety and it could be argued that anything less than 3 stars would be contrary to the duty of care employers have for their employees.

Of the vehicles assessed for fleets in 2021 by Euro NCAP many attained five stars, with the Nissan Qashqai coming out on top, just ahead of the Subaru Outback and the NIO ES8. The one to avoid, it would seem, is the Dacia Logan (two stars), which offered only ‘marginal’ protection to front seat occupants in various tests.

For more information on test programmes in different regions, please follow the links below: