CoastMaster: An Ambient Speedometer to Gamify Safe Driving.

We present CoastMaster, a smartphone application that serves as an ambient speedometer and driving game display. Our work is motivated by the need to re-engage drivers in the driving task, e.g., in situations where manoeuvering the vehicle is straightforward and does not require high levels of engagement. CoastMaster supports drivers during speed limit changes by (a) re-engaging them in the driving task, and; (b) providing feedback on driving behaviour. In a simulator study (N=24), we compare a gamified and a non-gamified interface with regards to user experience, driving performance, and visual distraction. Our results indicate an increase in hedonic quality and driver engagement as well as a decrease in speed violations through the gamified condition. At the same time, the gamified version leads to longer glances towards the display suggesting visual distraction. Our study findings inform specific design recommendations for ambient interfaces and gamified driving.