EURONCAP front crash test involves crashing a car moving at 64 kph onto a deformable barrier at 40% of the total vehicle width. According to the EURONCAP website, this is equivalent to two vehicles crashing into each other at 55 kph. How did they arrive at this figure? I presumed that the above mentioned crash-test would be equivalent to two cars moving at 32kph into each other. But, I am starting to get the idea that these relative velocity figures are better calculated by taking absorbed kinetic energy into account. Please provide me with some simple equations. Citation from the EURONCAP website: ''By carrying out frontal impact tests at 64km/h (about 40 mph) we are simulating a car impacting a similar sized car where both cars are travelling the same speed of 55 km/h.''