We have very advanced automotive technology like AWD these days to allow us to go off-road, but clearly not all cars can go off-road; how come in old movies you see old cars driving on dirt roads all the time?

Question

Is this just a movie thing? Aside from the lack of comfort, how well did old cars drive on dirt roads, which presumably were everywhere? I can’t imagine they got good traction on those thin wheels, or even produce enough power to push through a bumpy hill, so I’m wondering if there’s something I’m missing here?

In: Technology

Answer 1

Dirt or gravel roads aren’t a problem for normal cars, provided they are *graded* every few years, weather and traffic depending. The main limitation to cars is how flat the road surface is.

In general the speed of cars are limited on such roads because they deteriorate faster than asphalt or concrete. Therefore bumps, potholes, ponding, wash-outs, washboarding, flying gravel form much more quickly.

Grading involves using specialized dozer to clear high spots, then laying down additional gravel in-fill if needed, then rolling flat.