General Motors' Firebird II was described as having an "electronic brain" that allowed it to move into a lane with a metal conductor and follow it along.
An autonomous car, also known as a driverless car,self-driving car and robotic car, is an automated or autonomous vehicle capable of fulfilling the main transportation capabilities of a traditional car. As an autonomous vehicle, it is capable of sensing its environment and navigating without human input. Robotic cars exist mainly as prototypes and demonstration systems. As of 2014[update], the only self-driving vehicles that are commercially available are open-air shuttles for pedestrian zones that operate at 12.5 miles per hour (20.1 km/h).
Autonomous vehicles sense their surroundings with such techniques as radar, lidar, GPS, and computer vision. Advanced control systems interpret sensory information to identify appropriate navigation paths, as well as obstacles and relevant signage. By definition, autonomous vehicles are capable of updating their maps based on sensory input, allowing the vehicles to keep track of their position even when conditions change or when they enter uncharted environments.
Autonomous means having the power for self-government. Many historical projects related to vehicle autonomy have in fact only been automated (made to be automatic) due to a heavy reliance on artificial hints in their environment, such as magnetic strips. Autonomous control implies good performance under significant uncertainties in the environment for extended periods of time and the ability to compensate for system failures without external intervention. As can be seen from many projects mentioned, it is often suggested to extend the capabilities of an autonomous car by implementing communication networks both in the immediate vicinity (for collision avoidance) and far away (for congestion management). By bringing in these outside influences in the decision process, some would no longer regard the car's behaviour or capabilities as autonomous; for example Wood et al. (2012) writes "This Article generally uses the term "autonomous," instead of the term "automated." We have chosen to use the term "autonomous" because it is the term that is currently in more widespread use (and thus is more familiar to the general public). However, the latter term is arguably more accurate. "Automated" connotes control or operation by a machine, while "autonomous" connotes acting alone or independently. Most of the vehicle concepts (that we are currently aware of) have a person in the driver’s seat, utilize a communication connection to the Cloud or other vehicles, and do not independently select either destinations or routes for reaching them. Thus, the term "automated" would more accurately describe these vehicle concepts".
Level 3: The driver can fully cede control of all safety-critical functions in certain conditions. The car senses when conditions require the driver to retake control and provides a "sufficiently comfortable transition time" for the driver to do so.
Level 4: The vehicle performs all safety-critical functions for the entire trip, with the driver not expected to control the vehicle at any time. As this vehicle would control all functions from start to stop, including all parking functions, it could include unoccupied cars.
In Europe, cities in Belgium, France, Italy and the UK are planning to operate transport systems for driverless cars, and Germany, the Netherlands, and Spain have allowed testing robotic cars in traffic. In 2015, the UK Government launched public trials of the LUTZ Pathfinder driverless pod in Milton Keynes.
An increase in the use of autonomous cars would make possible such benefits as:
Fewer traffic collisions, due to an autonomous system's increased reliability and faster reaction time compared to human drivers.
Increased roadway capacity and reduced traffic congestion due to reduced need for safety gaps and the ability to better manage traffic flow.
Relief of vehicle occupants from driving and navigation chores.
Removal of constraints on occupants' state – in an autonomous car, it would not matter if the occupants were under age, over age, unlicensed, blind, distracted, intoxicated, or otherwise impaired.
Alleviation of parking scarcity, as cars could drop off passengers, park far away where space is not scarce, and return as needed to pick up passengers.
Elimination of redundant passengers – the robotic car could drive unoccupied to wherever it is required, such as to pick up passengers or to go in for maintenance. This would be especially relevant to trucks, taxis and car-sharing services.
Reduction of space required for vehicle parking.
Competition for the radio spectrum desired for the car's communication.
Self-driving cars could potentially be loaded with explosives and used as bombs.
Ethical problems analogous to the trolley problem arise in situations where an autonomous car's software is forced during an unavoidable crash to choose between multiple harmful courses of action.
Susceptibility of the car's navigation system to different types of weather. (As of 2014 Google's prototype has not driven in snow or heavy rain.) 
Autonomous cars may require very high-quality specialised maps to operate properly. These maps would be costly to produce for roads worldwide. Where these maps may be out of date, they would need to be able to fall back to reasonable behaviors.
Autonomous cars have to be able to respond correctly to police and other pedestrian gestures and non-verbal cues.
To function optimally autonomous cars need changes in road infrastructure with many design and cost implications. For example, traffic lights may need to be re-designed and upgraded to communicate with the vehicles and street lighting may need to be re-designed. These changes may have profound social, legal and financial implications.
If fully autonomous cars become commercially available they have the potential to be a disruptive innovation with major implications for society. The likelihood of widespread adoption is still unclear, but if they are used on a wide scale policy makers face a number of unresolved questions about their effects. One fundamental question is about their effect on travel behaviour. Some people believe that they will increase car ownership and car use because it will become easier to use them and they will ultimately be more useful. This may in turn encourage urban sprawl and ultimately total private vehicle use. Others argue that it will be easier to share cars and that this will thus discourage outright ownership and decrease total usage, and make cars more efficient forms of transportation in relation to the present situation.
U.S. States that allow driverless cars public road testing.
In the United States, state vehicle codes generally do not envisage — but do not necessarily prohibit — highly automated vehicles. To clarify the legal status of and otherwise regulate such vehicles, several states have enacted or are considering specific laws. As of the end of 2013, four U.S. states, (Nevada, Florida, California, and Michigan), along with the District of Columbia, have successfully enacted laws addressing autonomous vehicles.
In June 2011, the Nevada Legislature passed a law to authorize the use of autonomous cars. Nevada thus became the first jurisdiction in the world where autonomous vehicles might be legally operated on public roads. According to the law, the Nevada Department of Motor Vehicles (NDMV) is responsible for setting safety and performance standards and the agency is responsible for designating areas where autonomous cars may be tested. This legislation was supported by Google in an effort to legally conduct further testing of its Google driverless car. The Nevada law defines an autonomous vehicle to be "a motor vehicle that uses artificial intelligence, sensors and global positioning system coordinates to drive itself without the active intervention of a human operator." The law also acknowledges that the operator will not need to pay attention while the car is operating itself. Google had further lobbied for an exemption from a ban on distracted driving to permit occupants to send text messages while sitting behind the wheel, but this did not become law. Furthermore, Nevada's regulations require a person behind the wheel and one in the passenger’s seat during tests.
A Toyota Prius modified by Google to operate as a driverless car.
In 2013, the government of the United Kingdom permitted the testing of autonomous cars on public roads. Prior to this, all testing of robotic vehicles in the UK had been conducted on private property.
In 2014 the Government of France announced that testing of autonomous cars on public roads would be allowed in 2015. 2000 km of road would be opened through the national territory, especially in Bordeaux, in Isère, Île-de-France and Strasbourg.
Individual vehicles may benefit from information obtained from other vehicles in the vicinity, especially information relating to traffic congestion and safety hazards. Vehicular communication systems use vehicles and roadside units as the communicating nodes in a peer-to-peer network, providing each other with information. As a cooperative approach, vehicular communication systems can allow all cooperating vehicles to be more effective. According to a 2010 study by the National Highway Traffic Safety Administration, vehicular communication systems could help avoid up to 81 percent of all traffic accidents.
In 2012, computer scientists at the University of Texas in Austin began developing smart intersections designed for autonomous cars. The intersections will have no traffic lights and no stop signs, instead using computer programs that will communicate directly with each car on the road.
Through the implementation of Global Positioning System (GPS), navigation of the autonomous vehicles is simplified. The location of the vehicle can also be acquired by the longitude and latitude obtained by the GPS.
Public opinion surveys
In a 2011 online survey of 2,006 US and UK consumers by Accenture, 49% said they would be comfortable using a "driverless car".
A 2012 survey of 17,400 vehicle owners by J.D. Power and Associates found 37% initially said they would be interested in purchasing a fully autonomous car. However, that figure dropped to 20% if told the technology would cost $3,000 more.
In a 2012 survey of about 1,000 German drivers by automotive researcher Puls, 22% of the respondents had a positive attitude towards these cars, 10% were undecided, 44% were skeptical and 24% were hostile.
A 2013 survey of 1,500 consumers across 10 countries by Cisco Systems found a full 57% "stated they would be likely to ride in a car controlled entirely by technology that does not require a human driver", with Brazil, India and China the most willing to trust autonomous technology.
In a 2014 US telephone survey by Insurance.com, over three-quarters of licensed drivers said they would at least consider buying a self-driving car, rising to 86% if car insurance were cheaper. 31.7% said they would not continue to drive once an autonomous car was available instead.
Autonomous vehicles are still a developing technology; a large number of companies and researchers have speculated about future developments and the possible effects of the cars.
2015, Tesla will introduce "Autopilot". This feature combines automatic lane change (after signal is applied), adaptive cruise control, and sign recognition to regulate speed and location. It's expected to be the first vehicle manufacturer to offer automatic lane change.
2015, California will allow the testing of vehicles without wheels or pedals such as Google's on public roads. This will follow a 120-day grace period after a rule to be introduced in late 2014.
By the mid-2010s, Toyota plans to roll out near-autonomous vehicles dubbed Automated Highway Driving Assist with Lane Trace Control and Cooperative-adaptive Cruise Control.
By 2016, Audi plans to market vehicles that can autonomously steer, accelerate and brake at lower speeds, such as in traffic jams.
By 2016, Mercedes plans to introduce "Autobahn Pilot" aka Highway Pilot, the system allow hands-free highway driving with autonomous overtaking of other vehicles.
By 2016, Mobileye expects to release hands-free driving technology for highways.
In 2016 (2017 model year), GM plans to offer a "super cruise" feature on select Cadillac models, with autonomous lane keeping, speed control, and brake control, so that parts of trips can be made without touching the wheel or pedals.
By early 2017, the US Department of Transportation hopes to publish a rule mandating vehicle-to-vehicle (V2V) communication by an as-yet unspecified deadline. GM says that by the 2017 model year, the Cadillac CTS will be V2V equipped.
By 2018, Mobileye expects autonomous capabilities for country roads and city traffic.
By 2018, Nissan anticipates to have a feature that can allow the vehicle manoeuver its way on multi-lane highways.
By 2020, Volvo envisages having cars in which passengers would be immune from injuries. Volvo also claim vehicles will effectively be "crash free." 
By 2020, GM, Mercedes-Benz, Audi, Nissan, BMW, Renault, Tesla and Google all expect to sell vehicles that can drive themselves at least part of the time.
2020, ABI Research forecasts that truly self-driving cars would become a reality by 2020 and that 10 million such new cars would be rolling out on to United States' public highways every year by 2032.
By 2024, Jaguar expects to release an autonomous car.
By 2024, Google autonomous car project head's goal to have all outstanding problems with the autonomous car be resolved.
By 2025, Daimler and Ford expect autonomous vehicles on the market. Ford predicts it will have the first mass-market autonomous vehicle.
By 2025, most new GM vehicles will have automated driving functions as well as vehicle-to-vehicle communication technology.
By 2035, IHS Automotive report says will be the year most self-driving vehicles will be operated completely independent from a human occupant’s control.
By 2035, Navigant Research forecasts that autonomous vehicles will gradually gain traction in the market over the coming two decades and by 2035, sales of autonomous vehicles will reach 95.4 million annually, representing 75% of all light-duty vehicle sales.
By 2040, expert members of the Institute of Electrical and Electronics Engineers (IEEE) have estimated that up to 75% of all vehicles will be autonomous.
In 2014 Raj Rajkumar, director of autonomous driving research at Carnegie-Mellon University said that the artificial intelligence necessary for a driverless car would not be available "anytime soon" and that Detroit car makers believe "the prospect of a fully self-driving car arriving anytime soon is 'pure science fiction.'"
With Autonomous vehicles,
Columbia University's The Earth Institute forecasts the reduction of United States' fleet of vehicles by a factor of 10.
PricewaterhouseCoopers forecasts a reduction of traffic accidents by a factor of 10 and it concludes that the fleet of vehicles in the United States may collapse from 245 million to just 2.4 million.
KPMG LLP and the Center for Automotive Research (CAR) foresee improvements in productivity and energy efficiency as well as new business models.
Morgan Stanley estimates that autonomous cars could save the United States $1.3 trillion annually by lowering fuel consumption ($169 billion), reducing crash costs ($488 billion) and boosting productivity ($645 billion).
The 2002 film Minority Report, set in Washington, D.C. in 2054, features an extended chase sequence involving autonomous cars. The vehicle of protagonist John Anderton is transporting him when its systems are overridden by police in an attempt to bring him into custody.
The 2004 film I, Robot features autonomous vehicles driving on highways, allowing the car to travel safer at higher speeds than if manually controlled. The option to manually operate the vehicles is available.
"Driven", series 4 episode 11 of the 2006 TV series NCIS features a robotic vehicle named "Otto," part of a high-level project of the Department of Defense, which causes the death of a Navy Lieutenant, and then later almost kills Abby.
The éX-Driver anime series features autonomous electric-powered vehicles driven by Artificial Intelligences (AIs). These sometimes malfunction or are taken over by malicious users, requiring interception and intervention by éX-Drivers operating manually controlled gas-powered vehicles.
In "Sally" (first published May–June 1953), a short story by science fiction writer Isaac Asimov, autonomous cars have "positronic brains" and communicate via honking horns and slamming doors, and save their human caretaker.
^Gehrig, Stefan K.; Stein, Fridtjof J. (1999). Dead reckoning and cartography using stereo vision for an autonomous car. IEEE/RSJ International Conference on Intelligent Robots and Systems 3. Kyongju. pp. 1507–1512. doi:10.1109/IROS.1999.811692. ISBN0-7803-5184-3.|accessdate= requires |url= (help)
^Arth, Michael E. (2010). Democracy and the Common Wealth: Breaking the Stranglehold of the Special Interests. Golden Apples Media. pp. 363–368. ISBN978-0-912467-12-2. Arth claims that this would be possible if almost all private cars requiring drivers, which are not in use and parked 90% of the time, would be traded for public self-driving taxis that would be in near-constant use.