Hey Siri, take the wheel

Distracted driving is tied to 9% of fatal accidents in the U.S. For my thesis intern project at Volvo Cars, my partner and I researched voice assistants and wrote design guidelines to make them safer to use while driving.

My Role
  • User Research
  • Conversation Design
  • Prototyping
Company
  • Volvo Cars
Date
  • Spring 2019
Timeline
  • 6 months
Teammate
  • William Falkengren, Conversation Design & UX Research
Prototype of our in-vehicle voice assistant
We focused on voice assistants that integrate directly into the car, like our prototype shown here.

Voice assistants, like Siri and Google Assistant, offer drivers a hands-free, eyes-free way to complete secondary tasks such as replying to a text message. Are these voice assistants designed for safe driving or are they too good to be true?

How might we minimize distraction when using in-vehicle voice assisants while driving?

Research goals

  1. Identify and counter causes for visual distraction.
  2. Identify and counter causes for cognitive distraction.
  3. Leverage existing conversation design guidelines to emphasize safe use while driving.
Do and Don't for reducing cognitive distraction
While voice assistants offer hands-free interaction, phrasing a voice command could introduce distraction.

Quantitative data to support qualitative insights

Our methodology combined observations, surveys, and eye tracking data. From our on road tests, we found that drivers would be distracted by unresolved errors and robotic prompts from the voice assistant.

Eye-tracking software screenshot
With eye tracking data, we found that errors significantly increase visual distraction.

Helping drivers find the words

We created two prototypes to validate hypotheses for safer use while driving. The first aimed to reduce visual distraction by prioritizing shorter responses, presenting the most frequently used option to drivers. The second was designed to reduce the cognitive distraction of phrasing commands through longer contextual prompts from the assistant.

Voice prototypes used in simulator test
We used Wizard of Oz testing to evaluate our prototypes in a driving simulator.

New guidelines for safer use while driving

Combining insights from both our on road and driving simulator tests, we developed design guidelines for voice assistants. These guidelines were created to supplement existing guidelines and emphasize practices for safer interaction while driving.

Do and Don't for reducing visual distraction
Guideline Follow up on errors to prevent visual distraction.
Do and Don't for reducing cognitive distraction
GuidelineAdapt to driver’s vocabulary to ease cognitive distraction.
Do and Don't for handling difficult driving situations
Guideline Pause interactions during difficult driving situations.
Do and Don't for making the driver feel in control
Guideline Clear pathways in the conversation to make drivers in control.

Safety through partnerships

Volvo Cars is a brand dedicated to safety and innovation. At the end of our thesis project, we presented our findings and guidlines to the voice team within Volvo, who works with partners like Apple and Google to make integrated voice assistants safer to use for Volvo drivers.

Next Project

StageAR Desktop