Car controls

In the Ford Model T the left-side hand lever sets the rear wheel parking brakes and puts the transmission in neutral. The lever to the right controls the throttle. The lever on the left of the steering column is for ignition timing. The left foot pedal changes the two forward gears while the centre pedal controls reverse. The right pedal is the brake.

Car controls generally refers to the controls in automobiles and many other powered road vehicles. Many of which include trucks, buses, and specialized vehicles (e.g. heavy equipment), that are used for driving, parking, comforting passengers and safety. Modern car controls are now standardized, but this was not always the case. Controls are evolving in response to new technologies, for example the electric car.

Since the car was first invented, many of its basic controls have become fewer and simpler through automation. For example, all cars once had manual, physical controls for starting and running the engine, many of which have disappeared as automation took over their function. Meanwhile, new controls have also been added to vehicles, thus making them more complex. Examples include air conditioning, navigation systems, on-board computers, and in-car entertainment. Another trend is the replacement of physical knobs and switches with touchscreen controls. These may be limited to secondary controls as in BMW's iDrive and Ford's MyFord Touch, or may substitute an entire set of controls, as seen in vehicles by Tesla Motors.

While the following components usually apply to most road vehicles, there are some exceptions. The controls may be located and operated differently from road vehicles (such as motorcycles, whose throttle is controlled by a hand lever and the gear shift by a pedal). Additionally, some characteristics of road-vehicle controls may be found in rail vehicles. For example, some trams or light rail vehicles (most notably the PCC streetcar) use automobile-style pedals to control the speed, usually in conjunction with a dead man's switch.


1969 Citroen DS Pallas interior with hydraulic gear selector mounted top right of steering column with a single spoke steering wheel. Note the so-called mushroom brake pedal. (The pedal on the left is the parking brake).

Steering is the collection of components, linkages, etc. which allows road vehicles and any other form of guided transport to follow the desired course. The primary purpose of the steering system is to allow the driver to guide the vehicle. This definition including bicycles but excludes railed vehicles, in which rail tracks combined together with railroad switches (and also known as 'points' in British English) provide the steering function.

Although ships had used wheels for steering since the 1700s,[1] the first automobiles were steered with a tiller. In 1894, Alfred Vacheron competed in the Paris–Rouen race with a Panhard et Levassor with a steering wheel, which is thought to be the earliest deployment of the wheel.[2] From 1898, Panhard et Levassor cars came with steering wheels.

Steering wheels for passenger automobiles are generally circular, mounted to the steering column. Where cars drive on the left side of the road, the steering wheel is typically on the right side of the car, and vice versa.

Power steering makes it easier to turn the wheels. Power steering has mostly been hydraulic, but is now being replaced by electrical systems.


Hanging pedals in a Subaru Legacy. From left to right: foot rest, clutch, brake, gas.
Standing pedals in a Saab Sonett (clutch, brake, throttle)

The speed of guided vehicles is generally controlled using foot pedals. On smaller vehicles, these pedals usually hang from the bulkhead while on heavy-duty vehicles (especially on those equipped with air brakes) they typically stand on the floor. Regardless of where they are mounted, their arrangement is the same for both right- and left-hand traffic. From left to right:

Except for the parking brake, these pedals have a fail-safe design as they are equipped with springs that, in the case of the throttle, returns to the idle position when not depressed by the driver.

Normally the accelerator and brake are operated by the right foot, with the clutch operated by the left. However, there are drivers that practice Left-foot braking, though this is inefficient in general usage.


A floor-mounted gear lever in a modern passenger car with a manual transmission

Vehicles that generate power from Internal combustion engines are generally equipped with a transmission or gearbox to change the speed-torque ratio and the direction of travel (forward or reverse). This does not usually apply to electric vehicles as their motors can drive the vehicle both forward and reverse from zero speed and typically operate over a wider speed range than combustion engines.[3] In some four-wheel drive vehicles there is a gear lever that engages a low-ratio gearbox. Other levers may switch between two- and four-wheel drive, or engage differential locks.

Some cars have a freewheel that disengages the driveshaft from the driven shaft when the driven shaft rotates faster than the driveshaft. Saab used a freewheel system in their two-stroke models and maintained it in the Saab 96 V4 and early Saab 99 for better fuel efficiency, but at the cost of engine braking. Some cars, such as the Rover P4, included a manual switch to engage or disengage the freewheel.[4]


Manual transmissions feature a driver-operated clutch and gear stick. Historically, cars had a manual overdrive switch.


The desire for driver convenience has led to the widespread implementation of the semi-automatic transmissions, automatic transmissions and CVTs. Some automatic transmission vehicles have extra controls which modify the choices made by the transmission system depending on engine and road speed. Automatic transmissions traditionally have had a straight pattern beginning at the most forward position with park (which locks up the transmission), and running through reverse, neutral, drive (all gears available), and then the lower gears (often two or three more positions, each locking out a successive upper gear), with the rear-most position allowing first gear only.

Signalization and lighting

Cars include controls for headlamps, fog lamps, turn signals and other automotive lighting. Turn signals are activated by the driver on one side of the vehicle at a time to advertise intent to turn or change lanes toward that side.[5] Electric turn-signal lights date from as early as 1907.[6] The modern turn signal was patented in 1938, and later most major automobile manufacturers offered this feature.[7] As of 2013 most countries require turn signals on all new vehicles that are driven on public roadways. The turn signal lever is usually activated by a horizontal lever protruding from outward (left side for LHD, and right side for RHD) of the steering column. This enables drivers to be able to control the shiftier and the turn signals with different hands.


An analog speedometer using kilometres per hour (km/h). Immediately below is a digital odometer. Partially visible on the left and right are the tachometer and fuel gauge, respectively.

Vehicles are generally equipped with a variety of instruments mounted on the dashboard to indicate driving parameters and the state of the mechanics. They are usually mounted behind the steering wheel, although exact placement can vary; for example, they may be mounted centrally below the windshield, or integrated into the center stack above the climate control and audio system. The standard gauges found on road vehicles include the following, though not all of these may be found on any particular vehicle:

These gauges are supplemented by an assortment of warning lights that indicate the current status of various vehicle systems, including the currently selected transmission gear mode and the generic check engine light.

The layout and design of these instruments have evolved over the years, and more recently, have been implemented as digital readouts rather than the traditional analog dial-type indicators. Furthermore, depending on the type of vehicle, more specialized instruments may be used such as a trip computer, fuel economy gauge, or battery level display.

Starting and running the engine

1917 Packard crank holder

Before the advent of the starter motor, engines were started by various methods, including wind-up springs, gunpowder cylinders, and human-powered techniques such as a removable hand-crank. These were difficult and dangerous. The first electric starter was installed on an Arnold.[8] In 1911 Charles Kettering and Henry Leland invented and filed U.S. Patent 1,150,523 for the first electric starter in America. Starters were first installed on the Cadillac Model Thirty in 1912. Before Chrysler's 1949 innovation of the key-operated combination ignition-starter switch,[9] the starter was often operated by the driver pressing a button mounted on the floor or dashboard. This type of control has now returned because of the use of key-less entry. Early Chevrolets had the starter pedal to the right of the accelerator. Because it was difficult to operate this and the throttle pedal, there was a secondary throttle control knob on the dashboard.

Early cars such as the Ford Model T had a hand lever to control the throttle.[10] Later cars used both a foot pedal and a hand lever where the hand lever set the minimum throttle, an early form of cruise control. The 1918 Stutz Bearcat had a central throttle pedal with the clutch and brake to the right and left respectively.[11] Modern cruise control was invented in 1948.[12]

Other historical engine controls which in modern cars are automated include the choke valve, ignition timing, and spark arrestor.[13]


  1. "Only a tiller in hand -". Retrieved 2016-11-05.
  2. Duncan, H.O. (1927). The World on Wheels - Volume I. Paris. pp. 456–457, picture of the Vacheron–Car on p. 457.
  3. "2007 Tesla roadster". 2006-07-19. Retrieved 2011-09-01.
  4. "Rover P4 Manual". Retrieved 29 March 2014.
  5. Federal Motor Vehicle Safety Standards; Lamps, Reflective Devices, and Associated Equipment: Final Rule 12/04/2007
  6. U.S. Patent 912,831
  7. U.S. Patent 2,122,508
  8. G.N. Georgano (1985). Cars: Early and Vintage, 1886–1930. London: Grange-Universal. ISBN 1-59084-491-2.
  9. "Chrysler Family Debut", ''Popular Mechanics'' April 1949, p.122. Retrieved 2013-09-30.
  10. "The Ford Model T". Retrieved 29 March 2014.
  11. Leno, Jay. "1918 Stutz Bearcat". Retrieved 5 November 2016.
  12. Speed control device for resisting operation of the accelerator. Ralph R. Teetor. US-Patent 2519859 A
  13. "1928 Chevy Owner's Manual". Retrieved 30 March 2014.
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