“Hey, Hands on the Wheel, Bud!”

I’ve always noticed that ever since I bought my 2017 Prime. Nothing new. I occasionally don’t completely let go of the steering wheel, but hold it in such a way that the system thinks I’m not holding it, and it gives me that warning. Just a habit when I’m on a straight road.

Something stranger happened to me recently when it was raining hard and I was on a highway and the cruise control was on, suddenly I noticed the car would not slow down as it slowly approached the car in front of me. I had to intervene. Seems that the rain interferes with the sensors. After resuming cruise, it went back to normal.


iPhone ?

 

Page 387 in my manual. It's not new.

 

I've seen it frequently since I bought the car -- I have a light touch on the steering wheel I guess.

 

The users manual warns against using radar cruise in rain and snow storms.

 

The time until it alters you seems to depend on how straight the road is. Sometimes I've gotten the alert in a curve with both hands on the wheel. But on a straight section of highway I can go 30 seconds or more with my hands off the wheel before it alerts (I haven't timed it).

I assume if you drift towards the edge of the lane and lane departure assist kicks in while your hands are off the wheel, you might also quickly get an alert in that case, but I haven't tested it.

 

Yeah, it's pretty unpredictable. I only enable it for long trips just in cast I get drowsy. If I'm awake, I never cross the lines unless I intend to do so and then I don't want the car distracting me.

 

Crosswinds?

Minimum speed not reached?

 

Because I do cross the lines from time to time and don't want the message jumping in my face every time. Between that and the cruise control I'd never get to see what's supposed to be on the MID. Or else I'd wear out the "return" button clearing messages.

 

I have maintained early on that this should be flagged as a serious safety defect due to driver distraction.

Other manufacturers use lights to indicate radar cruise status. It is not urgent enough to need full page alerts that cannot be disabled!

 

And they think displaying music album art is distracting. Serious logic disconnect there.

 

Humm, I admit, this is the first time I have learned about he "Hands off steering wheel alert". I have never seen that alert on my PRIME. But, I have a feeling that I had it disabled along with other alerts that pops up on the MID.

My question is, how does the car know the hands are off the steering wheel? Is there touch sensor on the steering wheel? And if this alert comes on every time hands are off the steering wheel while driving, then what happens to those cars with Comma.ai installed?

 

It seems to measure rotation of the wheel. But it seems to be able to tell the difference from a rotation by the driver and a rotation caused by the wheels physically hitting something. It is also extremely sensitive, and the lightest rotation will dismiss the message. Maybe there is hardware (like a rotational strain gauge) that lets the Electronic Power Steering work, that can also be used to detect if the driver has hands on the wheel.

Besides the hands on the wheel alert, there is also the "coffee indicator" that reminds the driver to take a break. I think it comes on after 5 hours of continues driving, or if you trigger a lane departure alert too many times. I think it is configurable in the settings in the MID.