Robotaxi

A robotaxi (or "robo-taxi"), also known as a self-driving taxi or a driverless taxi, is an autonomous car (SAE automation level 4 or 5) operated for a ridesharing company.
The fact of eliminating the need for a human driver or chauffeur, which represents a significant part of the operating costs of that type of services, could make it a very affordable solution for the customers and accelerate the spreading of Transportation-as-a-Service (TaaS) solutions as opposed to individual car ownership. However, it raises the issue of job destruction.
Several studies highlighted that robotaxis operated in an Autonomous Mobility on Demand (AMoD) service could be one of the most rapidly adopted applications of autonomous cars at scale and a major mobility solution in the near future, especially in urban areas, providing the majority of vehicle miles in the United States within a decade of their first introduction. Moreover, they could have a very positive impact on road safety, traffic congestion and parking. Concerning pollution and consumption of energy and other resources, robotaxis could lead to significant improvement since these services will most probably use electric cars and for most of the rides, less vehicle size and range is necessary compared to usual, individually owned vehicles. The expectable reduction of the number of vehicles means less embodied energy but energy consumption for redistribution of empty vehicles must be taken into account.
Current status.
First operational tests and commercial ventures.
Several companies are testing robotaxi services, especially in Asia and in the United-States. In most tests, there are human chauffeurs or "safety drivers" in these test cars to take control back in case of emergency.
In August 2016, MIT spinoff NuTonomy was the first company to make robotaxis available to the public, starting to offer rides with a fleet of 6 modified Renault Zoes and Mitsubishi i-MiEVs in a limited area in Singapore. NuTonomy later signed three significant partnerships to develop its robotaxi service: with Grab, Uber’s rival in Southeast Asia, with Groupe PSA, which is supposed to provide the company with Peugeot 3008 SUVs and the last one with Lyft to launch a robotaxi service in Boston.
In August 2017, Cruise Automation, a self-driving startup acquired by General Motors in 2016, launched the beta version of a robotaxi service for its employees in San Francisco using a fleet of 46 Chevrolet Bolt EVs.
Uber.
In September 2016, Uber started allowing a select group of users in Pittsburgh to order robotaxis from a fleet of 14 modified Ford Fusions. The test extended to San Francisco with modified Volvo XC90s before being relocated to Tempe, Arizona in February 2017. In March 2017, one of Uber’s robotaxis crashed in self-driving mode in Arizona, which led the company to suspend its tests before resuming them a few days later. 
Waymo.
In early 2017, Waymo, the Google self-driving car project which became an independent company in 2016, started a large public robotaxi test in Phoenix using 100 and then 500 more Chrysler Pacifica Hybrid minivans provided by Fiat Chrysler Automobiles as part of a partnership between the two companies. Waymo also signed a deal with Lyft to collaborate on self-driving cars in May 2017. In November 2017, Waymo revealed it had begun to operate some of its automated vehicles in Arizona without a safety driver behind the wheel. By November 2019, the service was operating autonomous vehicles without a safety backup driver.
Tesla Robo-Taxi.
Tesla, Inc. announced a plan to launch a robo-taxi service by 2020. There were no active Tesla robo-taxis at the close of 2020.
According to Elon Musk, CEO of the company, Tesla will launch a transportation network. Car owners will be able to add or subtract their car from the network. In exchange, Tesla plans to take between 25-30% of the revenue. In places where there are not enough cars shared by car owners, Tesla said it would have dedicated Tesla vehicles. 
Other developments.
Many automakers have announced their plans to develop robotaxis before 2025 and specific partnerships have been signed between automakers, technology providers and service operators. Most significant disclosed information include: