1 of 1

User Vehicle Interface Design: Static Testing Methods

Maliyah Henry, Kathleen D. Klinich, Colleen M. Peterson

PROBLEM

Existing controls and displays may not accommodate drivers with vision, hearing, cognitive, or mobility disabilities.

RESEARCH QUESTIONS

  1. What existing standards could we borrow to improve usability of vehicle interfaces?
  2. How well do alerts and warnings work for people with different disabilities?
  3. What in-vehicle HMI elements improve usability across disabilities ?
  4. What controls and alerts could have the most impact on improving safety?

Vehicle Station

Warning Station

WHY THIS MATTERS

STUDY OVERVIEW

Participants rated warnings for:

  • Noticeability
  • Meaning
  • Urgency
  • Startle
  • Annoyance

Functional Assessment

People with disabilities are a part of an underrepresented population in vehicle design and HMI standards.

​

Making improvements to existing standards allows these individuals to have greater independence and improves driver safety and the user’s experience.

​

Goal: Evaluate user preference and the effectiveness of different blind spot warning designs. Warning variations included:

  • ISO blind spot warning symbol location (Upper left, Upper right, Lower left, Lower right)
  • Symbol Flashing Speed
  • Audio type (Tone or Speech warning)
  • Audio Volume

​

​

​

Goal: To evaluate the usability of vehicle interfaces while simulating driving. Tasks evaluated different climate controls, infotainment systems, physical controls, and identified minimum readable font and symbol sizes.

The design of static testing stations was informed by a literature review, online survey and focus groups with people with disabilities. Static test stations evaluated warnings, vehicle interfaces, participant’s capabilities and preferences regarding displays and terminology. The plots below show an initial distribution of participants by age and sex, as well as general disability type and level.

Goal: To quantify levels of participants’ self-reported disabilities.

Measurements:

  • Height(Sitting and Standing)
  • Weight
  • Vision(Far, Close and Color)
  • Hearing
  • Range of Motion (Head and Arm)
  • Memory (Nback)
  • ASD/ADHD
  • Seated Reach

Infotainment system visible font/color contrast:

•90% of participants could read 12 pt font, 98% 16 pt font

•Using a 16 pt font, readability of color schemes(Font color/Background color) from highest to lowest was G/W> W/B, W/G >B/R>B/C

Radio station selection task:

  • Keypad considered more challenging to use while driving than preset or scroll
  • Minimal variations in ratings across disability types
  • Most participants considered preset acceptable & keypad unacceptable

Climate control button size:

  • 9 mm button size more challenging to use while driving, and considered unacceptable by most participants
  • 12 and 15 mm button sizes received similar ratings of challenging to use while driving, but more participants found 15 mm size acceptable

The hearing test recorded minimum dB level to hear three frequencies, with and without ambient vehicle noise. Results show that even those with hearing disabilities can hear warning tones over ambient noise because they are different frequencies, supporting current recommendations to limit warning volumes to 15 dB above ambient noise.

Visible font/symbol size on steering wheel:

•100% of participants could see 10 pt font with AAA color contrast

•94% of participants could see 10 pt font with AA color contrast

•92% of participants could see 12 mm symbol height

Printing:

This poster is 48” wide by 36” high. It’s designed to be printed on a large-format printer.

​

Customizing the Content:

The placeholders in this poster are formatted for you. Type in the placeholders to add text, or click an icon to add a table, chart, SmartArt graphic, picture or multimedia file.

To add or remove bullet points from text, just click the Bullets button on the Home tab.

If you need more placeholders for titles, content or body text, just make a copy of what you need and drag it into place. PowerPoint’s Smart Guides will help you align it with everything else.

Want to use your own pictures instead of ours? No problem! Just right-click a picture and choose Change Picture. Maintain the proportion of pictures as you resize by dragging a corner.