Vehicle design has been an ever-changing field, and automakers are constantly introducing new features and improvements. However, some things have been around for years: steering wheels, rearview mirrors, windshield wipers, and so on.

But many of these things were once absent from vehicles, or only available as aftermarket options. For example, early automobiles used a tiller for steering before the wheel became more common.

These are some of the surprising stories of vehicle innovations over the years.

Cruise control

For cruise control, we have a blind engineer to thank – and perhaps a lawyer who was a lousy driver.

Ralph Teetor lost his vision in a childhood accident, but successfully pursued a career in mechanical engineering. He went on to become the lead engineer for the family company producing piston rings.

A federally imposed 35 mph speed limit during World War II may have helped inspire the idea of cruise control. The ability to automatically maintain a constant speed would drivers with this requirement, and Teetor received a patent for a cruise control device in 1945.

But family lore holds that Teetor was motivated more by the erratic driving of patent attorney Harry Lindsay, a friend who frequently chauffeured him. This story holds that Lindsay tended to slow down while talking and speed up while listening. If a vehicle feature could maintain a constant speed, Teetor wouldn't have to suffer such a jerky and uncomfortable ride.

The first "Speedostat" used a vacuum-driven piston to push back on the gas pedal once a desired speed was achieved; an electric motor would vary the throttle as needed. A driver could simply push against the resistance if they needed to speed up.

Chrysler was the first to introduce this device, under the name Auto-Pilot, in 1958. Other automakers soon adopted it as well, and the "Cruise Control" name introduced by Cadillac in 1959 proved to have staying power.

Teetor was originally opposed to the idea of locking in a speed so a driver could take their foot off the accelerator. He worried that people would become distracted or sleepy if they didn't have to focus on the accelerator. When automakers demanded this feature, he consented to upgrading the design to maintain speed until the driver pressed the brake pedal.

The OPEC oil embargo in 1973 helped spur the wider adoption of cruise control. As a 55 mph speed limit was imposed to reduce fuel use, cruise control was offered as optional equipment on most new vehicles.

Headlights and taillights

Early vehicle headlights housed kerosene lamps within reflectors. This feature was introduced in the 1880s, but wasn't very effective at illuminating the road ahead. Furthermore, the lights could be doused by rain or a gust of wind.

Vehicles then began to feature headlights fueled by acetylene gas tanks stored in the vehicle. But the reflectors used in headlights were still less than reliable, since they tended to be ineffective at focusing light.

Electric lights began to supplant gas systems in the 1910s, although they were also prone to blinding oncoming drivers. A dimmer was offered as an accessory in 1915, and Cadillac introduced depressible headlamps two years later. In 1925, the Guide Lamp Company launched a headlight bulb with two filaments, allowing drivers to switch between high beams and low beams. Sealed headlights, which use a reflector and lens, were introduced in 1939.

Early taillights, meanwhile, were originally meant to simply illuminate license plates. Drivers relied on hand signals to let tailing drivers know when they were planning to stop; brake lights did not appear until 1905, although 11 states mandated their use by 1928.

Turn signals

For quite some time, turn signals were not seen as an essential vehicle feature. Drivers could simply use hand signals to indicate if they were making a turn. Or, as many inconsiderate drivers do today, they could simply make the turn without offering any signal at all.

The first patent for a turn signal was issued in 1909 to Percy Douglas-Hamilton, whose idea consisted of a set of hands on either side of the vehicle which could be illuminated to indicate which way the driver wanted to turn. However, this system apparently never went into production.

Credit for the first practical turn signal is usually attributed to Florence Lawrence, who is also frequently described as Hollywood's first movie star. In 1914, Lawrence said she had developed an "auto signaling arm" for her vehicle: a flag located on the back fender that could be raised or lowered at the push of a button.

In addition to signaling which way she wanted to turn, her system had a stop sign which was automatically deployed when she hit the brakes. Lawrence never patented the device, so she never received any royalties from her inventions.

Several other patents for turn signals would be issued in the early 20th century, including one to Joseph Bell in the late 1930s for the first flashing signal. Electric turn signals were not offered by manufacturers until 1939, and did not become widespread until the 1950s.

Mirrors

When race car driver Ray Harroun saw a horse-drawn buggy with a mounted mirror to let the driver see to the rear, it inspired him to add a similar feature to his own vehicle. In this way, the rearview mirror became an unexpectedly controversial part of the first Indianapolis 500 in 1911.

Race rules stipulated that each driver must be accompanied by a mechanic. In addition to repairing the vehicle in the event of a breakdown, this person was meant to act as a safety feature. He would keep an eye out to the side and rear during the race, letting the driver know of any approaching vehicles.

Harroun was convinced that his own car wouldn't break down, so he persuaded race officials to exempt him from the rule. Instead of carrying a mechanic, he would use a rear-facing mirror to look for any potential hazards. In this way, he would cut the weight of his car and potentially gain an advantage in speed and fuel use.

The stratagem worked. Harroun won the race, although he later admitted that the brick pavers of the racetrack caused so much vibration that he couldn't reliably discern images in the mirror.

After this well-publicized use of an automotive mirror, rearview mirrors became more common. The location of the mirrors was up to the drivers. Added as aftermarket options, they appeared in varying places such as the front fenders or on top of side-mounted spare tires.

Side mirrors were not mandated until the 1960s, and were slower to gain popularity. As late as the 1970s, some models only came with a driver's side mirror, with a passenger side mirror available only as an optional add-on.

Electronic stability control

Electronic stability control uses sensors to measure data such as turning force, lateral acceleration, and the angle of the steering wheel to determine if the vehicle is traveling the way the driver wants it to. If not, it automatically activates the brakes on individual wheels or selectively uses the throttle to help restore control. The feature is especially useful during evasive maneuvers, as it helps prevent the vehicle from rolling over.

Although the system has its roots in traction control systems developed in the 1980s, the invention of electronic stability control is credited to engineer Frank-Werner Mohn. During a Mercedes-Benz test trip in 1989, Mohn lost control on an icy road in Sweden and wound up in a ditch. The incident inspired the idea of connecting a vehicle's antilock brake system to the onboard computer to make it more effective.

Electronic stability control was successfully tested in 1991. Mercedes-Benz began using it in production vehicles in 1995, followed soon after by Toyota.

The feature was originally used only on luxury models. But the need to extend it to a wider range of vehicles became apparent in 1997, when a journalist was able to flip a Mercedes A-Class microcar at 37 mph during the evasive maneuvers of a "moose test."

Mercedes responded with a design overhaul to include electronic stability control on the A-Class. As other manufacturers opted to install the feature on non-luxury models, Mercedes supplied the technology to them at no cost.

Heat and AC

An advertisement promoting the first automotive air conditioning appeared in 1933. The first factory-installed air conditioning was offered by Packard in 1940.

Air conditioning was a rather unpopular option, though, with just a few thousand cars equipped with it prior to World War II – mostly in the arid regions of the Southwest. The units were bulky, took up a great deal of trunk space, and could not reliably cool the front seats. Other problems included dripping condensation and the inability to circulate outside air.

In 1953, GM had figured out how to fit the air conditioning system in the engine compartment to offer more efficient cooling. Three years later, all automakers were offering air conditioning as an option.

More than half of all cars available in 1969 had air conditioning, and drivers could opt to have a unit installed at the dealership if one was not added at the factory. Due to concerns that Freon was contributing to the depletion of the Earth's ozone layer, a switch to a less harmful refrigerant was mandated by 1996. By this time, nearly all available models had air conditioning.

The first rudimentary car heaters circulated exhaust gases through pipes to radiate heat into the vehicle's interior. In 1933, Ford offered a gas-fueled boiler in the dashboard to provide heat.

GM created the heater core in 1930, using a fan to direct heat from the vehicle's coolant into the vehicle's interior. The same basic system is still in use today, with further developments creating climate control to create a mix of cool and warm air to create the optimum temperature.

Seat belts

The development of seat belts in vehicles descended from similar work in airplanes. Patents for vehicular safety harnesses were filed almost simultaneously with the introduction of motor vehicles, with the first one issued in the United States in 1885.

But there was little interest in such a feature. Automakers believed that if too much attention was given to safety features, drivers might conclude that the vehicle was unsafe. Race car drivers were also uninterested, believing that it was better to be thrown clear of a wreck than held inside by a seat belt – still a common misconception today.

Implementation came slowly. Some physicians, horrified by the serious injuries caused by car crashes, installed homemade seat belts on their vehicles. U.S. automaker Nash began offering lap belts in 1949, but the feature was withdrawn after a year.  Ford and Chrysler developed seat belts in 1956 and also found little demand for them.

Part of the problem was that early seat belts only crossed an occupant's lap. Lap belts were not only ineffective at protecting occupants, but they could also cause serious internal injuries in high-speed collisions.

A breakthrough came from Nils Bohlin, a former aerospace engineer who developed the modern three-point seat belt. This feature debuted in Volvo vehicles in 1959. Although Bohlin filed for a patent, Volvo opted to make the feature available to other manufacturers; on the 50th anniversary of this development, the automaker estimated that the three-point harness has saved at least a million lives.

Initially, though, it was met with skepticism. Frustrated by the public's disinterest, Volvo enlisted race car driver Orvar Aspholm to deliberately roll a PV 544 vehicle equipped with seat belts at auto shows and other events across Sweden. Thousands of people witnessed him emerge unscathed from each crash. Aspholm also climbed aboard a crash test sled for several simulated low-speed collisions to demonstrate how the belt prevented whiplash and kept the driver's head from impacting the steering wheel.

In the wake of these demonstrations, seat belt requirements quickly became common. Several states mandated seat belt use in the early 1960s. The Highway Safety Act of 1966 mandated that all cars come equipped with seat belts starting in 1968, with trucks to follow in 1972.

It would still take years of public awareness and law enforcement campaigns before drivers began using seat belts in significant numbers. The federal government even sought to mandate seat belt interlocks in 1974, requiring vehicle occupants to buckle up before the vehicle would start. However, this system proved unreliable and extremely unpopular, and it was quickly scrapped.

Airbags

The first patent applications for vehicle airbags were submitted in the early 1950s, but the system initially seemed impractical. Nevertheless, automakers and safety groups soon began showing a keen interest in airbags, believing they might even be more reliable than seat belts.

In 1968, Allen Breed was awarded the first patent for an electromechanical airbag system. This coupled a crash sensor with an airbag which would be inflated by a chemical reaction or gas held in a storage container.

Airbags were introduced as optional equipment on some models in the 1970s, but the oil embargo slowed their implementation. They became more widespread in the 1980s, with Mercedes-Benz offering them on all available models in 1986 and Chrysler making them standard in 1988.

In 1990, a head-on crash involving two Chrysler LeBarons in Virginia was thought to be the first collision between two vehicles equipped with airbags. At the time, it was estimated that just 2 percent of the vehicles on the road in the U.S. had the feature. Both vehicle occupants walked away with minor injuries.

However, there were also concerns that airbags presented a danger to children and other diminutive passengers. When front seat airbags became mandatory starting with 1998 models, automakers were switching to "depowered" airbags. While airbags originally deployed at speeds of up to 200 mph, the velocity of depowered airbags is considerably reduced to cut down on the risk of injury. Today, sensors and computers also work to deploy airbags in different ways based on the severity of the collision.

Windshield wipers

During a snowy ride on a New York City streetcar in 1902, Alabama businesswoman Mary Anderson noticed that the driver had difficulty seeing through the windshield. Before she reached her stop, she was sketching an idea for the first windshield wipers.

Anderson's concept involved spring-loaded wiper arms made of wood and rubber, attached to a lever manually operated by a driver. The wipers could also be removed so there was "nothing to mar the usual appearance of the car during fair weather."

Although she was awarded a patent for her "window cleaning device" in 1903, Anderson had no luck marketing her invention. Automakers told her that windshield wipers weren't practical and would be too distracting. Despite these assertions, windshield wipers soon became widespread on vehicles.

Robert W. Kearns would feel similarly jilted by automakers when he came up with the idea for intermittent windshield wipers. He patented this technology, which allows drivers to set how quickly the wipers will operated, in 1967. When he tried to introduce it to automakers, none expressed interest.

As with Anderson, however, automakers soon introduced intermittent wipers on their own. Kearns subsequently sued Ford for patent infringement in 1978, and hit Chrysler with a similar lawsuit in 1982.

The cases would be tied up in court for several years. In 1990, a jury concluded that Ford had infringed on Kearns' patent, but had not done so deliberately. Nevertheless, Ford agreed to pay Kearns $10.2 million; Chrysler later paid him $18.7 million.

It was something of a Pyrrhic victory. Kearns' lawsuits against GM and foreign automakers were dismissed, and much of the money he won went toward legal expenses. And while he had hoped to become a major manufacturer of intermittent windshield wipers, the courts didn't bar automakers from developing their own technology.

Cup holders

The closest thing to a cup holder in early vehicles may have been some accessories to aid motorists looking to stop for a picnic. The Model T even had a complete kitchenette designed to strap onto the running board, with features such as a folding table, ice box, and storage compartments for butter and eggs.

Eating and drinking in vehicles became more common in the 1950s with the popularity of drive-in restaurants and theaters. Some vehicle models began to include small cup holder depressions in the glove compartment, though these were not sturdy enough to use during travel. Amazingly enough, the 1957 Cadillac Eldorado Brougham even came with a magnetized glove compartment and four metal cocktail tumblers.

Cup holders designed for use during travel began to appear in the 1960s, almost by accident. Ford's Econoline van included a tray located near the floor, and the automaker realized that people were often keeping cups there. Worried that drivers might lose control of the vehicle while reaching for their drink, the automaker updated the design to include cup holders within easy reach. Chrysler would also stake a claim in the popularization of cup holders, saying they became more universal in the 1980s after they were included in the company's popular minivans.

An infamous lawsuit likely had a role in making cup holders nearly ubiquitous in vehicles. After an elderly woman suffered severe burns after spilling hot coffee on her lap while riding in a 1989 Ford Probe, she sued McDonald's and won a hefty settlement.

Although Ford was not named in the suit, the auto industry was likely spooked by the possibility that they could have been held liable. After all, the Probe had no cup holders. In particular, European automakers who had spurned the feature began to introduce cup holders not long after the litigation.

Glove compartment

A 1900 Packard model is thought to have one of the earliest examples of a glove compartment, since it offered a "boot or box forming part of the body." Other automakers soon followed suit. The storage box quickly came to be used for other protective wear, including driving gloves.

The popularization of the term "glove compartment," however, is usually attributed to Dorothy Levitt. A prominent "Edwardian motorist" and the first woman to race a car, Levitt penned a handbook entitled The Woman and the Car to offer a number of recommendations for female drivers. Although she recommended a full set of driving apparel, including a muffler and washable overall, she noted how the "little drawer under the seat of the car" was a perfect place to keep gloves.

Amusingly enough, Levitt also prophesied the glove compartment's use as a catch-all for all manner of vehicular detritus. The inventory of her under-seat drawer included an extra handkerchief, veil, powder puff, hairpins, and some chocolates.

Car radio

Early attempts at car radios proved unpopular due to their expense, bulky size, and massive antennas. While an aftermarket Motorola radio introduced in 1930 is considered the first successful car radio, it still required complex installation and the added cost of $130 – about a quarter of the price of a Model A Deluxe coupe. Nevertheless, orders came pouring in after the radio was demonstrated at the Radio Manufacturer's Show.

Vacuum tubes were used to power car radios for the first half of the 20th century. The FM band was included in car radios in 1952, with the AM/FM option debuting a year later.

Drivers interested in playing their own selection of music had, for a brief period of time, the option of purchasing a vehicle with a record player built in under the dash. Chrysler first introduced this option in 1956. Since competing record companies had different formats, the automaker opted to take a third option: designing its own "microgroove" format which could fit LPs on seven-inch records. A spring-mounted stylus was designed to resist bumps during travel.

While the system performed well in testing, it was less successful in practice. The bouncier suspensions of Chrysler's more economical cars meant that record players in these models frequently skipped. In addition, there were only a limited number of records compliant with the new format.

Chrysler discontinued its "Highway Hi-Fi" system in 1959, though it also tried to introduce turntables into vehicles produced in 1960 and 1961. A British system, featuring a load-in slot, survived through 1970.

Further developments to car stereos included the transistor radio in 1963, 8-Track players in 1966, and stereo sound in 1969. Cassette players became widespread in the 1970s and had a surprisingly long run, making their last appearance on the 2010 Lexus SC 430. However, it's worth noting that the popular British motoring program Top Gear also derided this model as the "Worst Car in the History of the World."

The first factory-installed CD player appeared in 1985. Today, these are starting to go the way of the audio systems before them as newer models incorporate satellite radio and streaming services.