Rui Salgado Carreira conducted research on designing the travel experience within public transportation systems. His PhD thesis identified passenger experience factors and incorporated them into new public transportation product-service system development. He conducted qualitative and quantitative studies on river cruises and regional/mid-distance buses to identify experience factors like cleanliness, comfort, and social environment. These factors impact customer emotions and loyalty. He developed a travel experience scale and extended Kansei engineering methodology to better incorporate the customer experience into transportation system design. The goal is to improve public transportation by developing it as an integrated product-service system that enhances the customer experience.