As part of the M³ "Green City Mainz" master plan, the state capital of Mainz has decided to expand car sharing in Mainz by adding 350 additional vehicles. Due to limited availability of private parking spaces and improved visibility, these will also be offered on public roads in the future. The legal basis for this is the Car Sharing Act, which came into force at federal level in 2017. Its contents will be incorporated into Rhineland-Palatinate's road traffic law in the first quarter of 2020, which will also give the state capital Mainz the opportunity to offer car sharing parking spaces on public roads. The car-sharing parking spaces will be allocated to one or more providers for special use in return for a fee as part of a transparent and non-discriminatory allocation procedure in accordance with the provisions of the Car-Sharing Act.

In the first step, 50 car-sharing parking spaces will be allocated across 25 stations in 2020. The macroscopic selection of future car-sharing locations is based on two different objectives. On the one hand, at least one car-sharing station should be available in all districts of Mainz so that residents of less centrally located suburbs also have the opportunity to benefit from car-sharing.