The first road trip was taken without permission
One morning in August 1888, Bertha Benz took her husband Karl's experimental three-wheeler without telling him and drove her two teenage sons 106 kilometres across Germany to visit her mother. Nobody had ever driven that far. There were no filling stations, so she bought fuel at a pharmacy. When a pipe blocked she cleared it with her hatpin, and when the wooden BRAKES wore out she stopped at a cobbler and had him nail on strips of leather — inventing brake linings on the spot.
She sent Karl a telegram when she arrived. The journey proved the machine worked outside a workshop, newspapers wrote about it, and the orders started coming. The route she took is now a signposted memorial road.
What happens when you press the pedal
Most cars still work the way that first one did. The ENGINE burns a fine spray of fuel in small explosions, thousands of them a minute, each shoving a piston down. The pistons spin a shaft, and the GEARS decide how much of that spin becomes speed and how much becomes pulling power. The BRAKES throw the energy away again as heat, the EXHAUST carries off the burnt gases, and the STEERING points the front TYRES.
An ELECTRIC car such as a TESLA does the same job with a fraction of the moving parts. Our electric cars puzzle, over in the technology category, covers how that version works.
Cheap because they were all identical
Cars were playthings for the rich until Henry Ford put the Model T on a moving assembly line in 1913. Rather than a team building one car from start to finish, each worker did a single job as the car came past them, and the time to build one fell from around twelve hours to about ninety minutes. The price fell with it, and by the early 1920s half the cars in America were Model Ts.
The famous line about customers having any colour so long as it was black had a practical reason behind it. The black paint of the day dried fastest, and a drying shed full of cars meant a production line standing still.
Mostly, cars just sit there
For all the engineering, the average car spends something like 95 per cent of its life parked. It sits outside a house all night, outside a workplace all day, and moves for less than an hour in between. Every one of those parked cars needs a space of roughly twelve square metres at each end of the journey, which is why so much of a town is tarmac.
That single statistic is behind most of the arguments about cars in cities — car clubs, park-and-ride schemes, congestion charges and the slow removal of parking from town centres are all attempts to get more use out of a machine that is stationary almost all the time.
The patent that was given away
In 1959 a Volvo engineer called Nils Bohlin designed the three-point seatbelt, the diagonal-and-lap strap fitted to every car today. It works because it spreads the force of a crash across the strongest parts of the body, the hips and the ribcage, and because a driver can fasten it with one hand without thinking.
Volvo then made the patent free for every other manufacturer to use, deciding it would do more good as a standard than as an advantage over rivals. Estimates of the lives saved since run past a million.