# How does my RAV4 know I am holding the steering wheel? **URL:** \ **Category:** In My Humble Opinion\ **Created:** [July 16, 2022, 6:48pm UTC](https://boards.straightdope.com/t/how-does-my-rav4-know-i-am-holding-the-steering-wheel/968060 "2022-07-16T18:48:45Z")\ **Posts on this page:** 13\ **Page:** 1
**Author:** ![mixdenny](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mixdenny/32/2962_2.png) [@mixdenny](https://boards.straightdope.com/u/mixdenny)\ **Post date:** [July 16, 2022, 6:48pm UTC](https://boards.straightdope.com/t/how-does-my-rav4-know-i-am-holding-the-steering-wheel/968060/1 "2022-07-16T18:48:45Z")
2021 Toyota RAV4. The car has LTA (Lane Tracing Assistance) and it works quite well. If the car approaches the edge of a lane it beeps and corrects the steering lightly. However, if you are using the radar assisted cruise control it is much more aggressive. On a narrow lane it keeps the car within a very small center zone and the car can feel like the wind is pushing it. It works OK on wide, normal lanes. I have carefully tested it and it is almost like a self driving car. It follows curves and can even follow the car ahead of you if it is locked on. I can take my hand off the steering wheel (keeping it nearly touching) and after a few seconds it beeps loudly and a red warning appears to place your hand on the wheel. All I have to do is place one finger on the wheel and it knows it. How? I am definitely not applying pressure to trip a touch switch. ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [July 16, 2022, 6:51pm UTC](https://boards.straightdope.com/t/how-does-my-rav4-know-i-am-holding-the-steering-wheel/968060/2 "2022-07-16T18:51:19Z")
I beleive it’s just monitoring for inputs (steering) from you. Doesn’t have to be anything big, just enough for the sensors to notice. Now, how it tells the difference between inputs from you and inputs from things on the road that ‘backfeed’ into the steering wheel, I don’t know (my Kia Niro EV does the same thing). > [@mixdenny](#): > > I am definitely not applying pressure to trip a touch switch. You could test that. Wear gloves or something else to create an electrical and air gap and it’s not going to give you any warnings. I’ll bet you could even attach something to the wheel so you could steer without your hands getting anywhere near the wheel, and I still doubt it would complain. I think the sensors are just that sensitive. Or, maybe I’m wrong. Maybe there’s some type of (inductive?) coupling going on. If that was the case I think the alert would still show up if you were (but you aren’t) to try driving while only touching the wheel with something non-conductive but ‘pass’ if you tried steering with something more like, say, a water balloon. But, I’m still pretty confident it’s just some sensitive sensors. If the steering is done with stepper motors, it might be able to get a reading directly from them. ---
**Author:** ![Si\_Amigo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/si_amigo/32/2877_2.png) [@Si\_Amigo](https://boards.straightdope.com/u/Si_Amigo)\ **Post date:** [July 16, 2022, 9:22pm UTC](https://boards.straightdope.com/t/how-does-my-rav4-know-i-am-holding-the-steering-wheel/968060/3 "2022-07-16T21:22:01Z")
It measures the force created by the weight of your hands. Hang a water bottle from the bottom of the wheel and it will self drive until it runs out of trackable lanes. I do no condone doing this because if you get into an accident you will void your insurance. Or you could die. ---
**Author:** ![elfkin477](https://avatars.discourse-cdn.com/v4/letter/e/a9a28c/32.png) [@elfkin477](https://boards.straightdope.com/u/elfkin477)\ **Post date:** [July 16, 2022, 9:26pm UTC](https://boards.straightdope.com/t/how-does-my-rav4-know-i-am-holding-the-steering-wheel/968060/4 "2022-07-16T21:26:46Z")
It doesn’t know if you’re holding it. I have a Toyota and occasionally see that warning when both hands are on the wheel but the road is straight so I haven’t _turned_ the wheel at all for a while. ---
**Author:** ![Tabco](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tabco/32/7644_2.png) [@Tabco](https://boards.straightdope.com/u/Tabco)\ **Post date:** [July 16, 2022, 9:46pm UTC](https://boards.straightdope.com/t/how-does-my-rav4-know-i-am-holding-the-steering-wheel/968060/5 "2022-07-16T21:46:45Z")
My '22 Crosstrek has a similar feature and through observation I’ve determined that it’s seeking turning input on the steering wheel to determine if my hands are holding it. On long straightaways on the freeway I sort of hang my left hand at around the 7-8 o’clock position with most of the weight of my arm resting on my lap. This is just enough weight on the wheel for the car to be satisfied that I’m holding it. ---
**Author:** ![Jackmannii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jackmannii/32/311_2.png) [@Jackmannii](https://boards.straightdope.com/u/Jackmannii)\ **Post date:** [July 17, 2022, 1:16pm UTC](https://boards.straightdope.com/t/how-does-my-rav4-know-i-am-holding-the-steering-wheel/968060/6 "2022-07-17T13:16:33Z")
> [@mixdenny](#): > > 2021 Toyota RAV4. The car has LTA (Lane Tracing Assistance) and it works quite well. If the car approaches the edge of a lane it beeps and corrects the steering lightly. However, if you are using the radar assisted cruise control it is much more aggressive. On a narrow lane it keeps the car within a very small center zone and the car can feel like the wind is pushing it. It works OK on wide, normal lanes. It’s one thing for a car to sound an audible warning when about to hit an obstruction - say, when pulling into a garage. It would drive me nuts if, every time the edge of a lane was “approached”, the car beeped at me. This is a good reminder to make sure that our next car gives the driver the ability to turn off the Helpful Safety Dictator, hopefully on a semi-permanent basis without having to shut it off every time we start the car. ---
**Author:** ![Si\_Amigo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/si_amigo/32/2877_2.png) [@Si\_Amigo](https://boards.straightdope.com/u/Si_Amigo)\ **Post date:** [July 17, 2022, 2:00pm UTC](https://boards.straightdope.com/t/how-does-my-rav4-know-i-am-holding-the-steering-wheel/968060/7 "2022-07-17T14:00:05Z")
My Nissan Rouge has a button that performs the function of turning off the audiable alerts and haptic feedback (vibration) in the steering wheel. Also stops the tapping of the brakes. You have to push it everytime. The reason you cannot permanently choose to turn them off is due to liability to the manufactures and Federal Highway and Saftey Regulations. Its a good thing to know if you are veering out of your lane. If you want to stop the warnings either use your turn signals when changing lanes or stay alert enough to maintain your position. These things are not going away anymore than seatbelts are going away. These signals also go off if another vehicle is getting near you. Nanny state you say, yes it is because too many people drive like idiots and kill people. They ruin it for everyone else. But I believe pushing the button doesn’t turn off collision avoidance features. Hope not because it saved me twice while driving fir Lyet and Uber. ---
**Author:** ![Jackmannii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jackmannii/32/311_2.png) [@Jackmannii](https://boards.straightdope.com/u/Jackmannii)\ **Post date:** [July 17, 2022, 5:03pm UTC](https://boards.straightdope.com/t/how-does-my-rav4-know-i-am-holding-the-steering-wheel/968060/8 "2022-07-17T17:03:37Z")
> [@Si\_Amigo](#): > > The reason you cannot permanently choose to turn them off is due to liability to the manufactures and Federal Highway and Saftey Regulations. ymore than seatbelts are going away. Not saying you’re wrong, but what federal regulations/laws specifically mandate use of safety technologies like alerts for straying out of lanes, and/or require that they can’t be turned off by the driver? ---
**Author:** ![Si\_Amigo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/si_amigo/32/2877_2.png) [@Si\_Amigo](https://boards.straightdope.com/u/Si_Amigo)\ **Post date:** [July 17, 2022, 5:15pm UTC](https://boards.straightdope.com/t/how-does-my-rav4-know-i-am-holding-the-steering-wheel/968060/9 "2022-07-17T17:15:59Z")
Its sometimes the auto manufactures lawyers that decide that the interpretation of the law deems it so based upon previous cases that they lost. If claimants in an accident can show that the technology existed and was applied to a particular model they would open themselves up to very large civil suits if they gave the customer the option to bypass the saftey features. Its the law of CYA. Still I agree that audible cues should not be required, if only because deaf people are allowed to drive. ---
**Author:** ![Northern\_Piper](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/northern_piper/32/5304_2.png) [@Northern\_Piper](https://boards.straightdope.com/u/Northern_Piper)\ **Post date:** [July 18, 2022, 5:38am UTC](https://boards.straightdope.com/t/how-does-my-rav4-know-i-am-holding-the-steering-wheel/968060/10 "2022-07-18T05:38:56Z")
> [@elfkin477](#): > > occasionally see that warning when both hands are on the wheel but the road is straight so I haven’t _turned_ the wheel at all for a while. That would not be a useful feature in Saskatchewan. ---
**Author:** ![Hampshire](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hampshire/32/4887_2.png) [@Hampshire](https://boards.straightdope.com/u/Hampshire)\ **Post date:** [July 18, 2022, 8:33pm UTC](https://boards.straightdope.com/t/how-does-my-rav4-know-i-am-holding-the-steering-wheel/968060/11 "2022-07-18T20:33:03Z")
> [@Si\_Amigo](#): > > The reason you cannot permanently choose to turn them off is due to liability to the manufactures and Federal Highway and Saftey Regulations. I have a 2018 Tiguan that allows me to toggle the lane assist function off/on and I do not need to turn it off every time I get in the car. Haven’t had it on for a couple years now. ---
**Author:** ![Si\_Amigo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/si_amigo/32/2877_2.png) [@Si\_Amigo](https://boards.straightdope.com/u/Si_Amigo)\ **Post date:** [July 18, 2022, 9:08pm UTC](https://boards.straightdope.com/t/how-does-my-rav4-know-i-am-holding-the-steering-wheel/968060/12 "2022-07-18T21:08:08Z")
I’m not surprised. Different car companies will interpret things such as risk differently. But then VW did misinterpret how mileage calculations on their diesel engines were made a few years ago and it cost them a lot of business and good faith. YMMV! Also in 2018 the technology was less defined and widespread, its becoming more of a common feature and may eventually become standard. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [July 18, 2022, 10:53pm UTC](https://boards.straightdope.com/t/how-does-my-rav4-know-i-am-holding-the-steering-wheel/968060/13 "2022-07-18T22:53:41Z")
> [@Si\_Amigo](#): > > But then VW did misinterpret how mileage calculations on their diesel engines were made a few years ago They did a hell of a lot more than “misinterpret mileage calculations”. They flat-out cheated emissions testing by detecting that a test was being performed and changing behavior if so. They probably caused hundreds or thousands of excess deaths by cheating the regulations.