As I have commented before - no accident has a single 'cause'. There are always multiple factors, and, of course, speed is often a factor. But it is rarely the major factor. Statistical data suggests the major factor is alcohol.
But I have to agree with Pickles -a major factor underlying most accidents is the driver attitude. And, despite all the talk about increased safety of cars, stricter enforcement etc, the general improvement in the accident rate over the last fifty years is underpinned by improvements in attitude.
To give an example (and there could be lots of other examples given), today it is, for most people, considered almost unthinkable to drive while over the limit (and empirical data supports this - random breath tests never even come close to1% of tests being positive). Fifty years ago (or even less) the most common attitude was "How can I drink and not get caught?" Certainly there are a few still with this attitude, but far from being the norm, these are now outliers.

