Since February 2009 Euro NCAP has published a single overall safety rating
When Euro NCAP started crash testing new cars in 1997 it published two star ratings for each car – an adult occupant protection rating taking account of performance in frontal and side impact tests, and a pedestrian protection rating.
The maximum rating for both pedestrian protection and adult occupant protection was four stars, but after a few years, as car design was improved, Euro NCAP raised the bar and started using a maximum rating of five stars for adult occupant protection.
Since February 2009 Euro NCAP has published a single overall safety rating (up to five stars) made up from the weighted average of scores in four areas: adult occupant, child occupant, pedestrian, and a new area, 'safety assist'.
To achieve a high overall rating the car must deliver a balanced performance across all four areas: adult occupant protection, child occupant protection, pedestrian protection and safety assist.
Euro NCAP's engineers can apply 'modifiers' to the scores achieved in the laboratory crash tests to take account of the risk of injury to occupants of different sizes (the dummies used represent the average adult male) in different seating positions.
Since 2009 the results of an additional rear impact/whiplash test to assess the protection offered by the driver and front passenger seats has been incorporated into the adult protection rating.
Euro NCAP uses 18-month-old and 3-year-old sized dummies in the frontal and side impact test. The child restraints used are those recommended by the vehicle manufacturer.
Euro NCAP also carries out a number of child seat installation checks using best-selling 'universal' child restraints to assess ease of installation, location of seatbelt buckles and access to anchorage points. The availability of ISOFIX anchorages in multiple seating positions is also taken into account.
Pedestrian protection tests have been a feature of the Euro NCAP programme since it began but up until 2009 the results were published as a separate star rating. This had only a very limited effect on car design as both manufacturers' and consumers' focus was on the adult occupant protection rating.
Since 2009, scores achieved in the pedestrian protection tests have formed part of the overall safety rating and to get a good score in this, vehicles must deliver a balanced performance across all areas including the pedestrian tests. It is hoped that this will help to encourage more pedestrian-friendly vehicle designs.
A series of component tests using head and leg-form impactors assess the risk of injury to adult and child pedestrians when struck by the bumper, bonnet leading edge and bonnet top.
The first three ratings above assess the injury risk to car occupants and vulnerable road users in the event of a crash, but car manufacturers are focussing more and more of their efforts on developing active systems that can help prevent crashes occuring in the first place or at least reduce their severity. It'll be a long time before airbags are made
redundant but the potential for fatality and injury reduction through the adoption of intelligent safety assistance systems is significant.
Euro NCAP is encouraging fitment of such systems with it's Safety Assist rating and by ensuring that cars must score well in this area in order to achieve a good overall safety rating.
Manufacturers have been awarded points (contributing towards the adult occupant protection rating) for seatbelt reminder systems since 2003 but these now form part of the Safety assist rating alongside speed assistance systems and electronic stability control. More systems with proven injury reduction potential are likely to be incorporated into the Safety assist rating over the coming years.
(updated 19 April 2013)