In the real world we have licenced taxis which are insured and inspected. Unlike in America that doesn't mean they can get minor medical treatment for exorbitant fees and nothing. The drivers are tested before they can get a licence, they even check to see if they have a criminal record. The taxi is tested to a higher standard than the standard annual test on cars. The meter is inspected to make sure it isn't rigged. It is difficult for muricans to understand that laws and regulations are actually enforced and not just used for imprisoning poor people, apartheid, and oppression.
This libertarian wet dream taxi service is as stupid as any other libertarian neocon notion. Subverting the rules and regulations which have been shown to be necessary for public safety just isn't a concept indoctrinated gun licking Americans understand.