<p>The whole focus on larger size and weight to crash into other cars ignores the fact that half or more of car crash fatalities are in single vehicle crashes.</p>
<p>Wrapping your big SUV around a big tree or rolling it down the ravine is not a situation where larger size and weight can help – indeed, the extra size and weight make it harder to avoid a crash, and mean that there is more energy to have to dissipate when you do hit something.</p>