Autonomous (also called self-driving, driverless, or robotic) vehicles have long been predicted in science fiction and discussed in popular media. Recently, major corporations have announced plans to begin selling such vehicles in a few years, and some jurisdictions have passed legislation to allow such vehicles to operate legally on public roads.
Levels of Autonomous Vehicles (NHTSA 2013)
Level 1 – Function-specific Automation: Automation of specific control functions, such as cruise control, lane guidance and automated parallel parking. Drivers are fully engaged and responsible for overall vehicle control (hands on the steering wheel and foot on the pedal at all times)
Level 2 - Combined Function Automation: Automation of multiple and integrated control functions, such as adaptive cruise control with lane centering. Drivers are responsible for monitoring the roadway and are expected to be available for control at all times, but under certain conditions can disengaged from vehicle operation (hands off the steering wheel and foot off pedal simultaneously).
Level 3 - Limited Self-Driving Automation: Drivers can cede all safety-critical functions under certain conditions and rely on the vehicle to monitor for changes in those conditions that will require transition back to driver control. Drivers are not expected to constantly monitor the roadway.
Level 4 - Full Self-Driving Automation: Vehicles can perform all driving functions and monitor roadway conditions for an entire trip, and so may operate with occupants who cannot drive and without human occupants.
There is much speculation concerning autonomous vehicle impacts (Polzin 2016). Advocates predict that consumers will soon be able to purchase affordable self-driving vehicles that will greatly reduce traffic and parking costs, accidents and pollution emissions, and chauffeur non-drivers, reducing roadway costs, eliminating the need for conventional public transit services (Keen 2013). Under this scenario, the savings will be so great that such vehicles will soon be ubiquitous and virtually everybody will benefit. However, it is possible that their benefits will be smaller and their costs greater than these optimist predictions assume
Potential Impacts (Benefits and Costs)
Advocates predict that autonomous vehicles will provide significant user convenience, safety, congestion reductions, fuel savings, and pollution reduction benefits. Such claims many be overstated. For example, advocates argue that because driver error contributes to more than 90% of traffic accidents, self-driving cars will reduce crashes 90% If they feel safer, vehicle occupants may reduce seatbelt use, other road users may become less cautious, vehicles may operate faster and closer together, and human drivers may be tempted to join autonomous vehicle platoons, which will introduce new risks and enforcement requirements. Millard-Ball (2016) suggests that pedestrians to become less cautious and responsible around autonomous vehicles.
Estimated congestion and parking cost reductions, energy savings and emission reductions are also uncertain due to interactive effects. For example, the ability to work and rest while traveling may induce some motorists to choose larger vehicles that can serve as mobile offices and bedrooms and drive more annual miles.
Self-driving taxis and self-parking cars will require empty backhauls. Although the additional vehicle travel provides user benefits (otherwise, users would not increase their mileage) it can increase external costs, including congestion, roadway and parking facility costs, accident risk imposed on other road users, and pollution emissions. Some strategies such as platooning may be limited to grade-separated roadways, so human-driven vehicles may increase congestion on surface streets. Autonomous vehicles may reduce public transit travel demand, leading to reduced service, and stimulate more sprawled development patterns which reduce transport options and increase total vehicle travel.
The incremental costs of making autonomous vehicles are uncertain. They require a variety of special sensors, computers and controls, which currently cost tens of thousands of dollar but are likely to become cheaper with mass production (KPMG 2012). However, because system failures could be fatal to both vehicle occupants and other road users, all critical components will need to meet high manufacturing, installation, repair, testing and maintenance standards, similar to aircraft components, and so will probably be relatively expensive. Autonomous vehicle operation may require special navigation and mapping service subscriptions (this explains the Google Corporation’s interest in this technology) Other, simpler technologies add hundreds of dollars to vehicle retail prices. For example, GPS and telecommunications systems, review cameras, and automatic transmissions typically cost $500 to $2,000. Navigation and security services such as OnStar and TomTom have $200 to $350 annual fees. Autonomous vehicles require these plus other equipment and services.
Autonomous Vehicle Equipment and Service Requirements
Diverse and redundant sensors (optical, infrared, radar, ultrasonic and laser) capable of operating in diverse conditions (rain, snow, unpaved roads, tunnels, etc.).
Wireless networks. Short range systems for vehicle-to-vehicle communications, and long-range systems to access to maps, software upgrades, road condition reports, and emergency messages.
Navigation, including GPS systems and special maps.
Automated controls (steering, braking, signals, etc.)
Servers, software and power supplies with high reliability standards.
Additional testing, maintenance and repair costs for critical components such as sensors and controls.
Manufacturers will need to recover costs of development, ongoing service (special mapping and software upgrades) and liability, plus earn profits. This suggests that when the technology is mature, self-driving capability will probably add several thousand dollars to vehicle purchase prices, plus a few hundred dollars in annual service costs, adding $1,000 to $3,000 to annual vehicle costs. These incremental costs may be partly offset by fuel and insurance savings. These average approximately $2,000 for fuel and $1,000 for insurance per vehicle-year. If autonomous vehicles reduce fuel consumption by 10% and insurance costs by 30%, the annual savings will total about $500, which will not fully offset predicted incremental annual costs.
Autonomous vehicles can be programed to optimize occupant comfort. Le Vine, Zolfaghari and Polak (2015) argue that because vehicle passengers tend to be more sensitive to acceleration than drivers, and occupants use travel time to work or rest (autonomous vehicle illustrations often show occupants playing cards or sleeping) it is plausible that for comfort sake users will program their vehicle for lower acceleration/deceleration characteristics than human-powered
vehicles, leading to reductions in total urban roadway capacity.
Some advocates claim that self-driving capability will result in more vehicle sharing, including self-driving taxis and more sharing of private vehicles (Fagnant and Kockelman 2013; ITF 2014; Schonberger and Gutmann 2013). Sivak and Schoettle (2015b) estimate that, by allowing household vehicles to serve multiple residents, for example, taking a commuter to work and then transporting other household member for errands, they could reduce vehicle ownership up to 43%, and increase travel per vehicle by up to 75%. However, these impacts are difficult to predict. There are many reasons that motorists may prefer a personal rather than shared vehicle, for status, because they frequently keep tools or carry dirty loads in their vehicles,because they drive high annual miles, or because they need assistance provided by human drivers Shared autonomous vehicle cost profiles are likely to range between carsharing ($0.60- $1.00 per vehicle-mile, including ownership, operation and administrative costs) and human-operated taxis ($2.00-3.00 per vehicle-mile including ownership, operation, administration and labor costs).
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