I think LKA is a great safety feature for circumstances like you described. We all know that LKA is not a substitute for attentiveness while driving. Instead, as you suggest, I use LKA as an extra layer of safety, just in case I'm distracted or my mind wanders more than I'm aware. In the meantime, LKA has reminded me that I have developed the habit of forgetting to use my turn signal when changing lanes. The ATP with LKA is an expensive option and is only available on the Gen 3 Package V. Nevertheless, if it saves your life or the life of another person, the added security of LKA is a bargain. Otherwise it is an entertaining gadget that reminds me to use my turn signal.
Actually it does steer for you as well. It won't do any steering for you until the very last minute much like PCS wont brake for you until the very last minute. When it does steer, it wont self correct once you get to the center of the lane like LKA. I find the LKA and LDW work best at night because the white lines and reflectors makes the lane markers very visible when the LED headlights shine on them.
Actually you're wrong. The LKA will swerve left and right if you don't control it. LDW is even worse.
I agree. If you let LKA steer your car, you will appear like a drunk driver as your car bounces from one side of the lane to the other.
No, LDW steers as well. Before I bought the Prius I too though that LDW only notifies until after I bought it and tried it out.
Then why the distinction between the two?? LDW below 50mph and LKA above 50mph? Did you try it at speeds below 50mph?
LKA actively steers for you and keep you in the center of the lane. You constantly feel the steering wheel tucking and nudging. LDW does not have that feeling. The steering wheel feels natural and free until you're almost driving on the lane marker then it beeps and steers you away from the lane marker. LKA does counter steer when the car is at the center of the lane to keep the car in the center of the lane while LDW does not.
I get what you're saying, but why differentiate between the two in terms of steering? You might as well say LKA works in conjunction with LDW to steer.
I'd clarify on your point that the LKA is continuously applying torque to the steering wheel, but won't keep you in the center of the lane, as you mentioned before. I've tried letting it steer itself, and it basically bounces side to side in the lane like a kid's bowling ball going down a lane with bumpers, if it even steers strong enough to prevent you from leaving the lane. (If you approach the edge of a lane at a fairly steep angle, for example, the LKA system won't apply enough torque to keep the car from leaving the lane.) You can feel the steering torque change without going all the way to the edge, like when you get to a curve, the steering wheel feels different for sure - as long as the car doesn't think you're about to leave the lane, it feels a little harder to move it at first, and if you're in a curve, it takes little to no effort to stay in the curve because the motor holds the steering wheel in place against the forces that would naturally straighten the car out. But it won't keep the car in the middle of the lane. I've never tested LDW much, but the manual does say that it provides a "sensory warning*" in addition to the beeping and MID message, "*: A slight steering torque is applied for a short period of time in the direction of the center of the lane." So it will steer a bit as you leave the lane.
But it's doing exactly what the name implies if CProAudio's description is correct. Most LDW systems have an alert (sensory or audible) but don't nudge you back. It's nice that Toyota includes it in its LDW. Now LKA, as the name implies, keeps you in your lane so I can understand the distinction as it applies torque to keep you in the centre of the lane. It's basically an advanced version of LDW and doesn't let you get close to the edge of your lane.
One could argue that Lane Departure Warning should only serve to warn, not correct. On the other hand, the LDW's steering away from the lane marker is no different from Lane Keep Assist, which is keeping the car within the lane. It's usually divided into two different systems, one that serves only to warn and one that warns and corrects. In other words, it's all semantics.
Actually LKA and LDW feel very different. With LDW, once it nudges you away from the lane divider, it wont straighten out. It will as Macman said. LKA constantly applies torque to the steering to try to keep you in the center of the lane. That's why when you let go of the steering wheel, it starts to veer side to side until the angle is too steep to correct and eventually it'll steer itself out of lane. However, when the LKA is set and tracking lanes, if you start to veer off to the side, LKA will steer back to the center of the lane. Here's what LKA will do that LDW wont. It counter steer to straighten itself out so you don't veer to the opposite side of the lane marker. LDW will not counter steer to straighten itself out.
Well that's how I envisioned it. Well then, we'll just settle on the fact that Toyota took LDW one step further and nudge you back. You guys (USA) are the only ones in the world that get LKA on a Prius so I can't check it out (Though I would like to have the feature when I do drive down the US, which is fairly often)
