The Effects of Using Taxi-Hailing Application on Driving Performance

Driver distraction has become a major threat to the road safety, and the globally booming taxi-hailing application introduces new source of distraction to drivers. Although various in-vehicle information systems (IVIS) have been studied extensively, no documentation exists objectively measuring the extent to which interacting with taxi-hailing application during driving impacts drivers' behavior. To fill this gap, a simulator-based study was conducted to synthetically compare the effects that different output modalities (visual, audio, combined visual-audio) and input modalities (baseline, manual, speech) imposed on the driving performance. The results show that the visual output introduced more negative effects on driving performance compared to audio output. In the combined output, visual component dominated the effects imposed on the longitudinal control and hazard detection; audio component only exacerbated the negative effects of visual component on the lateral control. Speech input modality was overall less detrimental to driving performance than manual input modality, especially reflected in the drivers' quicker reaction to hazard events. The visual-manual interaction modality most severely impaired the hazard detecting ability, while also led to strong compensative behaviors. The audio-speech and visual-speech modality associated with more smooth lateral control and faster response to hazard events respectively compared to other modality. These results could be applied to improve the design of not only the taxi-hailing application, but also other input-output balanced IVIS.