This post describes single user experience with putting tactile aids on car controls. Doing this can cause dangerous confusion and is not recommended to the reader. Please see the warning at the bottom of this post.
Have you ever eaten trail mix while driving? No need to look into the bag to make selections: M&Ms, cashews, or raisins are easy picking thanks to the sense of touch or haptics, which is how fingers “see”. Munching while motoring inspired me to experiment with putting haptic stickers in different locations in my car. These stickers have different shapes or bumps on their surface that can be easily recognized by the way they feel.
I wanted to learn whether these stickers would improve my driving experience so I put them in 3 places:
- On the cruise control cancel button on the right panel of the steering wheel that was beside my right thumb.
- On the drive button on the panel between the front seats to the side of my right thigh.
- On the heads-up display on the dashboard panel.
Here is what I found:
- For steering wheel buttons that adjust cruise control, my right thumb moved back and forth between the toggle that adjusts speed to the cancel button that has a haptic sticker on its surface. The sticker consisted of a plastic bump that makes it easy to feel. The speed toggle switch was also easily distinguished by
touch without the need to look down from the road. If these 2 controls were not recognizable by touch, I would need to look down from the road frequently to operate the cruise control. This would be impractical and possibly dangerous., especially because of a special need that I have. I have a right ankle arthritis from a previous injury. When safely possible, pressing cruise control buttons on the steering wheel to adjust the car’s speed is more comfortable for me than foot pedal movement.
- For the center panel drive button, some reaching was needed to press the drive button (orange
haptic sticker). I was able to locate it without looking down most of the time, but sometimes need to visually guide the position of my hand. When sight was not used, I could keep my eyes on the road which reduced distraction. Also, feeling the distinct tactile feature of the drive button reassured me that I was making the selection I desired, though I took special care to avoid confusion.
3. For the dashboard smart screen, haptic stickers made it easier for me to select my favorite
radio stations without looking away from the road. Reaching out to the screen required much more spatial awareness of where my hand and my target was compared to my steering wheel experience. With practice, I became more comfortable with making radio selections and keeping my eyes on the road. I likened this to groping for pieces of trail mix, except this time the groping was for radio stations. I memorized the association between the position and feel of the haptic stickers with my favorite stations and flipped between them readily, keeping my eyes on the road. Without memorization, my recollection of what each haptic control selects would be aided by windshield projection of the items and corresponding haptics (video illustration).
Conclusion. With adage “hands on the wheel, eyes on the road”, my experience suggest that adding tactile features to cabin controls is useful and an improvement in my user experience of driving. I believe the most useful place where haptic should be is where the hands are, which is the steering wheel. This reduced my need to look away from the road. Research is needed to determine how a greater integration of haptics in cars impacts driver safety and distraction.