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?

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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

I know it was a lot tougher in the past, vehicles stuck in mud was practically a defining feature of the world wars. Apparently 4-wheel drive (different than AWD in that it powers each axle rather than each wheel) was invented in 1893, I have no idea how common it was on vehicles though. I think by the second world war when you had jeeps and APCs designed for off-road use they must have had 4WD standardized by then. In the first world war it seems like wheeled vehicles were confined a lot more to paved or well-maintained dirt roads, and if you had rough ground to cross you’d probably be more likely to do it with a horse than a car, but I couldn’t pinpoint when exactly that changed either

Either way, interesting question

Some of the earliest cars rolled off the assembly lines and onto “roads” that were cut by horse and buggy. Meaning many of the roads had slits on them that the wheels sort of went into. Dirt or grass isn’t really an issue for any car nor has it been as long as it’s dry and not very steep.

Modern AWD in consumer land are usually to help with Winter conditions, but of course some are made for dealing with more aggressive terrain or trail conditions. If you go back to early automobiles they simply were not used in these applications, horses were still common modes of transport to be used if needed.

Many of the features that makes a car a good off road vehicle makes it a poor highway vehicle. Features such as soft suspension, high ground clearance and soft tyres makes them consume more gas and can cause them to more easily tip over. Off road vehicles also tend to prefer low weight solution to help them climb better and not sink into soft ground as easily. However that makes them dangerous in high speed accidents as they have no crumple zones and the luxury in them are quite bad. A classical off road vehicle even tends to be a soft top which makes them impossible to heat or cool, it makes a lot of wind noise at speed and they tend to leak in the rain. So in general you have to chose between a good highway vehicle or a good off road vehicle unless you want to challange the laws of physics.

In the past cars were better off road. Part of this is that they were lower price and therefore lower weight as they were built with less material and less luxury features. But it was also because roads tended to be much worse and you therefore needed a car that could handle some mud and snow and rough terrain. Most roads were just horse tracks with minor upgrades when the car came along. It was first in the 60s and 70s when the major highways were constructed that people actually had smooth roads to go on and would need highway cars. But there were still a lot of local roads that could not be traveled on with any car.

There’s a big difference between a dirt road and “off-road.” Dirt roads are leveled and cleared of rocks and can be maintained by being smoothed out to prevent ruts forming. The roads are often in a path that has natural good drainage, not necessarily the shortest route. The early development of the automobile actually coincided with the “Good Roads Movement” that tried to improve roads, often with better maintenance of dirt roads rather than with expensive paving.

The safe driving speed on a dirt road is lower. Cars also used to break down a lot more than they do now, and especially so on bad roads.

My bog standard, 2WD MPV is perfectly fine driving on a field, or down a crappy dirt track.

It can’t handle large rocks/bumps, very steep gradients, deep/very slippery mud e.t.c – and neither could these “old time” cars.

Dirt roads in the past were the only roads. Typically only inside towns and cities had cobblestone or hard paved road. Once you left the city, all you had was bare dirt, oiled dirt or gravel roads.

An experiment with the us army in 1919 trying to cross the country lead to the birth of the us interstate highway system and a paved network of roads from coast to coast.

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.

This always impressed and baffled me, too!!

I live in the Interior of Alaska and we have an awesome museum dedicated to the different vehicles and other means of conveyance that look more fragile than my 2004 AWD MommyMobile from the mid 1900s.

How did/were they able to successfully drive through terrain that mine can’t?