Stan,
On this subject, You are right, we have one of the highest statistics of deaths on the road
Various factors lead to this:
1) Reckless driving, drivers will overpass others in very narrow routes regardless of how near/far the cars/buses on the opposite lane are.Or even in curves. Or driving beyond speed limits even when the weather advises the opposite. The Ezeiza accident some days ago is a good example of Argentineans disrespect for laws/lives, one shouldn't be driving that fast in foggy conditions. And Ezeiza is well known for its fog, so it should have come as no surprise.
2) Condition of routes. Ruta 7 (which accounts for a good deal of argentine agriculture transportation with one truck after another) is a good example it should be widened, in some stretches it even has no "banquina". We have one of the most expensive tolls (thanks to the privatizations) and yet the routes are far from safe.
3) Condition of cars, many of them should be banned from circulating. No proper lighting, brakes etc
This combination is many cases fatal. You should be always on alert when driving in Argentina. One can be driving safe but you never know what to expect about the others.