Autonomous vehicle industry is developing by leaps and bounds. We envisage a situation where autonomous vehicles act as taxis to transport clients. During the transportation, vehicle sharing is enabled and encouraged. We propose fair allocation in payment for passengers of a shared vehicle. The allocation is endowed with the characteristics of envy freeness and maximin utilities. Furthermore, we devise working mechanisms for autonomous vehicles, including (i) planning routes with minimum detour; (ii) choosing clients to recommend vehicle sharing; (iii) carrying passengers continuously. Our work may serve as a good preparation for the marketization of autonomous taxis.