Automation in road public transportation has been facilitated by the emergence of infocommunication and vehicle technologies. The widely accepted definitions of automation level focus solely on the driving aspects of vehicles. However, automation covers even more fields: service planning and management, vehicle and traffic control, and passenger-handling functions. Therefore, the main outcome of this paper is a method to be applied for the handling of complex automation levels, which gives a more comprehensive assessment of new transport technologies and mobility services. Functions and function categories are all described. The paper defines four levels of automation, with a detailed description of each level and each function. The method can be applied efficiently to the analysis and comparison of services, thereby highlighting possible fields of development. Mobility services can be described by values only in a general and simplified manner. To demonstrate the applicability of the proposed method, existing services are assessed. Dial-a-bus service, taxi, ride sourcing, and car sharing are evaluated using the novel method, which provides an objective and comprehensive comparison of these services.