Driving is the controlled operation of a vehicle, which is usually a motor vehicle such as a truck, bus, or car. For bicycles, mounted animals (not including chariot operation) and — at least in the United Kingdom, the United States and Canada — motorcycles, the corresponding activity is usually called riding (although operation of a bicycle is sometimes called bicycle driving).
Driving includes knowing how to operate the mechanisms which control the speed and direction (which in technical terminology are both components of the velocity), and the braking of the vehicle, and especially includes knowing how to do both safely. An experienced driver usually has an intuitive understanding of the basics of car handling.
In terms of the basic physical tasks required, driving a motor vehicle generally involves:
Of course, driving is far more complicated than simply pressing pedals and turning the steering wheel; it also involves looking out for everyone (and everything) else on the road. The skill of safe driving is necessary to avoid collisions, which kill many thousands of people annually (see also car accident).
Safe driving is much more than following the legally prescribed rules of the road. It goes beyond that into the cultivation of good habits, maintaining attention, and a thoughtful, cooperative attitude that help to avoid and prevent accidents. This is often described as defensive driving.
Motorists are almost universally required to take lessons with an approved instructor and pass a driving test before being granted a license. The trend has been towards increasingly tougher tests in recent decades. Almost all countries allow all adults with good vision to apply to take a driving test and, if successful, to drive on public roads. Saudi Arabia, however, bans women from driving vehicles (whether pedal or motor powered) on public roads. Saudi women have periodically staged driving protests against these restrictions.
In many countries, even after passing one's driving test, new drivers may be initially subject to special restrictions. For example, in Australia, novice motorists are required to carry "P" ("provisional") plates, and are subject to lower speed limits, alcohol limits, and other restrictions for their first two years of driving. This varies between states.
Each country has its own unique way of dividing up the responsibility for enforcing all the laws mentioned above. In nearly all countries, though, the laws controlling driving in practice (like speed limits) are enforced by the police, who are in the best position to identify violations as they occur and to issue citations or make arrests.
Some countries, like Australia, prefer to put everything road-related into a single agency at the state level. Thus, in the Australian state of New South Wales, the Roads and Traffic Authority (RTA) is responsible for driver licensing; highway construction, maintenance, and patrol; and many other things. Policing on Australian roads is provided by the relevant state police.
In contrast, in the United States, many U.S. state governments have a Department of Transportation that handles road construction and maintenance (subject to some guidance from the federal Department of Transportation), and a separate Department of Motor Vehicles that handles driver licensing and vehicle registration. There is usually a state police agency (called the Highway Patrol or Department of Public Safety) which enforces driving laws on state highways. On local roads, driving laws are enforced by county sheriff's departments or city police departments.
In many jurisdictions, bicycles are legally considered to be vehicles and cyclists are legally classified as drivers. The use of bicycles is rarely subject to licensing. However, some municipalities require permits for bicycles.