Technological Evolution in the Swiss Bus Fleet from 1940 to 2022: An Inventory and Database for Research Applications

(1) Background: A strategic approach to managing and evolving the bus fleet is essential for optimizing public transportation, improving service efficiency, meeting future demands, and incorporating environmentally friendly technologies. However, country-specific data on fleet composition and evolution are often lacking despite their importance in evaluating technological impacts on the environment, passenger comfort, and driver working conditions. This report describes the creation of the inventory of the Swiss bus fleet and analyzes technological developments in bus vehicles from 1940 to 2022. (2) Methods: We collected the data through a comprehensive mapping study and validated it with Swiss bus companies and experts from the Federal Office of Transport. Vehicle approval forms were used to extract technical data. Buses were sorted by brand and model. For each bus model, 58 technical characteristics were documented in a database. A latent class analysis (LCA) was conducted to classify the buses according to their technological characteristics. (3) Results: The inventory comprises 891 bus models, classified into four groups representing different generations. The predominance of thermal buses and the emergence of hybrid and electric buses since 2010 were noticed. (4) Conclusion: This inventory tracks bus technology evolution and highlights potential implications for driver occupational exposure and environmental impact assessment.