Introducing of an efficient and high quality public transport system capable of retaining existing customers as well as attracting private vehicle users has become an urgent need. The effort in this study was therefore dedicated to understand how commuters make travel decisions with respect to different public transport service quality attributes and related factors. The findings revealed that the existing public transport system is not satisfactory from both private vehicle users and existing customers’ perspective. The results of Principal Components Factor Analysis pointed out, action taken to encourage a mode shift to public bus transport should address easy accessibility, on board comfort, punctuality, service reliability, safety and security.