The European New Car Assessment Programme has been running since the mid-1990s. It's accepted as the standard for car safety - although not all cars are tested, making comparisons of less popular cars difficult. See www.euroncap.com for detailed test results.
Euro NCAP rates car safety according to the extent of injuries sustained by crash-test dummies in front- and side-impact collisions. Top rating was originally four stars, but a five-star system is now used.
Safety standards have improved rapidly thanks to better vehicle design and wider fitting of airbags. Most cars tested since 2000 achieve a three- or four-star rating. A small but growing number rate five stars.