Values of a variable affecting the determination of the driver of a shared ride may be calculated. Each value may be associated with a respective potential driver. An optimal value from the calculated values may be selected. A potential driver associated with the selected optimal value may be assigned as the driver of the shared ride. The variable may be carbon emission, electricity consumption, passenger to driver role ratio, driving distance, driving time, vehicle size, fuel efficiency, electricity to gasoline usage ratio, accident occurrence, vehicle safety, vehicle comfort, or vehicle speed. The optimal value may be the lowest value or the highest value from the calculated values. Each value may be calculated based on parameters specified by the respective potential driver.