A bus route map is considered the primary means to provide passengers with the information of the bus company’s operating network. Hence, it becomes an essential wayfinding tool for the passenger. However, bus route map design also largely depends on how easy the map is to understand, and a successful design delivers the intended purpose of aiding users in understanding and navigating the network. This paper aims to investigate a bus route map’s usability, focusing on the effectiveness of its design elements to gain knowledge for future design improvement of Transjakarta’s route map. A two-part study was conducted to understand the level of users’ ease of understanding regarding route design elements. First, a map-reading experiment was conducted comparing two maps designed strictly based on Transjakarta’s route map design. Participants were asked to search for specific busstops and routes by reading the map while the search time was recorded. Second, an interview was conducted to gain insight into users’ preferences regarding easy-to-understand design elements. Results showed that attributes and information related to the route line (route number, colour, how the route line is drawn)directly affected passenger decisions in wayfinding, whereas route line colour has the most significant impact on how the participant read the map, impacting the success of wayfinding while using the map.