An Integrated Fuzzy Approach for Alternative-Fuel Bus Selection in Sustainable Public Transportation

There is a growing global awareness of the need for more efficient and sustainable transportation systems. A vital part of urban transportation systems are buses. This study presents a hybrid approach for the selection of the right fuel type for buses in public transportation. It considers economical, technological, environmental, social, and risk criteria simultaneously. In this approach, we first evaluate criteria weights by Chang’s Fuzzy Analytical Hierarchy Process (FAHP) and then determine the best alternative-fuel bus by Fuzzy Axiomatic Design (FAD) for the municipality of Izmir, the third largest city of Türkiye. Several sensitivity analyses were conducted with different criteria weights, design ranges, weighting and ranking methods. The results show that there is no significant difference between Chang’s and Buckley’s criteria weights and the ranking of Fuzzy TOPSIS is slightly different than FAD. Five fuel types were evaluated. Results from FAD indicate that electric buses are the most sustainable option. Sensitivity analyses confirmed the robustness of this ranking under various weighting schemes. In the scenarios emphasizing economical, environmental, and technical criteria, electric buses remained the top choice for FAD, while social and risk weighting favored CNG and Biodiesel options, respectively. The findings offer practical implications for municipal decision-makers.