A report from the NRMA, reprinted almost verbatim in the SMH, shows that if you’re in a single-vehicle collision in a 4WD, you’re more likely to be injured than in a passenger car. So why do suburbanites drive 4WDs?
To find the answer, you need to go beyond the NRMA’s spin, and check out the report itself. So far as I can tell, it’s this one (big PDF file, sorry), released in June. And the answer to the conundrum is buried on p.115. If you’re in a 4WD and hit a medium-sized car, there’s an 8.4% chance you’ll go to hospital or the morgue. If you’re in the medium car and hit a 4WD, there’s a 15.3% chance of serious injury.
These days, we’re rapidly moving from one equilibrium to another. Medium car-medium car collisions carry an 11.9% injury risk. 4WD-4WD collisions carry a 14.3% injury risk. US researcher Michelle White calls the phenomenon an "arms race" on our roads (I wrote a little piece on it last year).
Since two-vehicle accidents are more common than single-vehicle accidents (p.14 of the report), 4WD owners are probably acting rationally. But I also suspect that since most people think they’re a better driver than the average driver, buyers worry more about two-vehicle accidents than they really should — which would further skew buyers towards 4WDs.