Effects of speech-based vs handheld e-mailing and texting on driving performance and experience

In this paper we present a voice-enabled service for handling email and SMS messages while driving, and an evaluation of the service. In the evaluation, driving performance was compared in three conditions with a highway driving scenario in a driving simulator: driving only, driving in combination with voiceenabled handling of e-mail/SMS messages, and driving in combination with handheld handling of e-mail/SMS messages. Both objective measurements and subjective judgments about driving performance were collected. The results showed that drivers increased the headway when performing an additional task. With respect to the subjective measures, drivers felt that driving only was safest, and that voice-enabled interaction was safer, enabled better concentration and a better driving performance than handheld interaction. We conclude that handheld interaction is felt to have a stronger impact on driver performance and workload than voice-enabled interaction.