The wheel has turned slowly but surely for over a century.
It's generally considered to be the world's first production car, and Karl Benz invented technology to make it work, but the 1885 Benz Patent-Motorwagen didn't have a steering wheel. Instead, it used a horizontal bar with a handle mounted to a directly vertical bar we would now call the steering column. It also had three wheels; steel-spoked wheels and solid rubber tires; one gear, and used a chain drive. After that, it took a while for the basic recipe of what we recognize now as a road car to be perfected - four wheels with air-filled tires, a multi-gear transmission, floor-mounted pedals for the brake, and accelerator, and a round steering wheel. You might find a flat part at the bottom of a steering wheel in a sporty car to emulate race cars where drivers are stuffed into a tight cockpit, but even flat-bottomed wheels are generally just that, round wheels. Occasionally an automaker might try to develop a rectangular control for steering, but there's a reason the steering wheel has been largely the same for well over a hundred years. However, that doesn't mean the steering wheel hasn't evolved into what we use to steer our cars today.
It's impossible to pinpoint the exact first use of a steering wheel, but the first one we can definitively point to is a Panhard 4 hp model raced by Alfred Vacheron in France in 1894. In 1898, Panhard set about fitting steering wheels to one of its production cars, and by 1914 the steering wheel became the standard way to steer a car. In 1898, a British inventor and founder of the Rambler brand mounted the steering wheel on the left side of the car. By 1910 automakers had followed suit as standard in Europe, and America soon followed.
Once the steering wheel became commonplace, someone had the bright idea of mountain the car's warning horn control in the center. The 1915 Scripps-Booth Model C is the first car we can identify that used the arrangement using an electric switch rather than a pneumatic bulb. Scripps-Booth also added a spare wheel as standard for the first time to the luxury Model C, and the first push-button door lock to a car. Founder James Scripps Booth left the company in 1916 but left one hell of a legacy on the automotive industry with his engineering and artistic sensibility. Chevrolet bought Scripps-Booth in 1919 but the brand was retired by General Motors (GM) in 1923.
Other arrangements to activate the horn have been tried, but there's still no better solution than in the center of the steering wheel. Our favorite was Ford's solution of building the horn control into the outer rim and marketing it as the "Rim Blow" steering wheel.
Tilt adjustment on steering wheels came along with the mass adoption of the steering wheel. Early on, it required loosening a locknut before resetting once the wheel was in the desired position. Telescopic adjustment to bring the wheel closer or further from the driver didn't show up on production cars until 1949, courtesy of Jaguar and the XK120 roadster. Ford brought a similar design to the masses in the 1955 Ford Thunderbird.
The idea of power steering was floating around in the 1920s to reduce the effort needed to steer cars, trucks, and buses. American inventor Francis W. Davis initially developed it and quickly signed a contract for the technology with GM. Unfortunately, the Great Depression delayed it being used on Cadillac cars and Yellow Coach buses. The delay carried on after due to World War II, so it wasn't until 1951 power steering made it onto a production car, the Chrysler Imperial. Since then, hydraulic power steering has been the standard, but we're currently in a transition to fully electrical systems.
According to lore, cruise control for cars was invented in 1948 by the American engineer Ralph Teetor. The idea came to him while he was riding as a passenger with his lawyer, who was speeding up and slowing down while he talked. The most amazing thing about that story is that Teetor was blind in both eyes from childhood, yet still managed to live life as if he had never been blinded. Initially, cruise control was operated by a lever, and the first car with Teetor's system was the 1958 Chrysler Imperial and its 'Auto-Pilot' function. In 1960, automakers started mounting the control on the steering wheel. The 1966 Ford Thunderbird's steering wheel was the coolest with its single bar and two switches mounted for the cruise control, whether it was the first or not.
One issue with the standard system for mounting a steering wheel was that, in an accident, the steering wheel was an immovable object at the chest height of the driver. If the steering wheel broke, the steering column became a spear. Two things happened by law to reduce fatalities in 1968 in the US. The first was that seatbelts were required to be fitted to every production car, the second was the requirement for collapsable steering columns. In the 1950s, Ford had looked at the problem and came up with a steering wheel with spokes that flexed, but a column that collapses upon an impact is the solution still with us today. Chevrolet got to production first in 1967 with a system that used a two-piece column with a steel mesh that crumpled under pressure and let the column telescope freely.
Intuitively, we wouldn't blame anyone for thinking the Germans first thought to mount audio controls on the steering wheels, but Mercedes was curiously way behind with that. Instead, it was likely a Japanese Domestic Market (JDM) car in the late 1970s or early 1980s that first mounted volume controls on the steering wheel. The first non-JDM car we can trace back to be sold in the US is the 1984 Nissan 300ZX Turbo 50th Anniversary Edition, but it's telling that Nissan reflects on the car's steering wheel controls as "advanced for the time," and not the first. That was when the technology started going mainstream, though.
The development of the airbag was a long one. The first patent can be traced back to 1920 for airplanes, while the first patent for automotive use was filed by the German engineer Walter Linderer in 1951 but wasn't approved until 1953 after the US approved a patent for John W. Hetrick. Nothing really came of the patents until after they had expired, and Ford started experimenting in 1971 and GM in 1973. Under the law, shoulder belts, as opposed to just lap belts, were required unless airbags were fitted, so GM marketed its airbag system as a replacement for shoulder belts. Airbags are now dedicated as a supplemental restraint system (SRS), but the first to offer one was Mercedes as an option as early as 1981. Porsche, though, sealed the deal by making a driver and passenger SRS airbag standard equipment in the 1987 Porsche 944 Turbo. Chrysler then furthered the cause in 1988 by making airbags standard equipment throughout its range.
In 1990, the first collision between two cars fitted with airbags was recorded between two 1989 Chrysler LeBarons in a head-on collision. Both drivers walked away with minor injuries despite both cars being completely wrecked.
Early steering wheels were built using a metal substrate covered by wood. However, it was expensive and could split - hence; race car drivers wore driving gloves whatever the weather. Over time, wood has been replaced by plastics as the main material, and became decorative on luxury vehicles. Early plastics included polyoxybenzylmethylenglycolanhydride, better known as by its brand name Bakelite, and covering the steering wheel with leather to give a nicer feel, and more grip to the wheel became popular in the 1960s. Unless you're specifically buying a crazy high-end car now, chances are the leather-wrapped steering wheel is made using plastic-based faux leather. Mostly, steering wheels are now covered with a synthetic resin or polyurethane, although wood, carbon fiber, and other exotic materials are used on high-end models, albeit without the original splintering properties.
Connecting the steering wheel rim to the hub is where steering wheels have changed the most in construction over time. Early on, four spokes were the most common configuration, but over time, that changed to three. Four-spoke wheels still haven't ever gone away as an aesthetic choice, though. In Europe, Citroen used a single-spoke arrangement for a long time, including on the celebrated classic DS model from the 1970s.
A butterfly, square, or oblong shape for the rim is still the preserve of race and concept cars outside of gimmickry. The UK's Austin Allegro is a notable example and had a square steering wheel marketed as "quartic," but was derided by the automotive press and consumers alike.
Earlier than that, Plymouth used a similar design called the "Aero Wheel" for the same reason. Basically. The design of the cars didn't allow enough room for people's legs underneath the wheel. Just looking at one, though, and you can work out the design flaw in the "fix" that will become painfully apparent when the "wheel" is turned.
Flat-bottom wheels do show up in some road cars, but it's more often for the appearance of being sporty than practical reasons and end up being annoying when you have to maneuver the vehicle in and out of a parking space. When push comes to shove, there's a reason steering wheels in road cars have evolved but not re-invented in over 125 years. And, now we've said that, watch Chevrolet prove us wrong with the Corvette.
It's hard to predict the future, but in 2021, we've already seen some interesting wheels. While the Corvette has a squared-off wheel, the Aston Martin Valkyrie goes one step further with a completely rectangular one. Aston has a history of doing odd tillers, though, and the special one-off Aston Martin Victor finally rolled off the line earlier this year sporting a race-inspired yoke. Speaking of the yoke, we'd be remiss not to mention Tesla here with the Model S Plaid. While we can't say it's the most intuitive design we've seen, we expect a lot more adaptation as we move towards autonomy, with BMW even patenting a steering wheel that folds in order to hide away when in autonomous mode. Whatever the future holds, we can be certain that the steering wheel will likely remain similar in form until it's done away with entirely.