How does lane departure prevention work?

[Wilbursan]

I have an M37X AWD with LDP and it doesn't seem to do anything. The warning works fine, annonyingly so sometimes. But if I let the car continue to cross the lane it will just keep going, nothing brings it back. And yes, it's turned on. I assume I can't be putting any input on the steering wheel when I do this - is there some other requirement? Like a car in the other lane or something?

[Ilya]

You should feel the car brake the opposite side of the car from the lane you're drifting into.

[Larz]

That depends on whether your car has the extra option for 'active' lane departure. My 09 (M35) has both. It has the basic feature which beeps at you but does nothing else, but it also has a button on the steering wheel that switches an active system on. If I activate that button, the car brakes and corrects but ONLY if I begin to leave my lane (even when using the steering wheel) without using the turn indicator. If I use my indicator, no beeps and no corrections.
The M37 has a different steering wheel so not sure where your active LDW button might be.

[Wilbursan]

That was it. I had the menu item turned on to enable it but there was also a button on the steering wheel that needed to pressed. I'll go play with it tomorrow and see how it works.

Thanks Larz!

[Frog]

On the new q there actually has to be a car in your blind spot or fast closure rate with a car in front of u. For it to do anything but beep at u.

[InfinitiAce]

It should just beep if you cross the lane, not actually brake. It should brake if there is a car in that lane. It will apply the brakes and pull you back. My wife's car has it. It drives me crazy. I prefer to just pay attention while driving.

I had a Q50 loaner car. I was backing out of a parking spot and it slammed on the brakes because a car stopped like 25 feet away from me. I could have done donuts in the space between me and the other car. Better safe than sorry I guess.

[Ilya]

Larz is right.

If you just turn on the warning (on the panel by the left knee), it'll beep. If you turn on active lane monitoring/intelligent cruise (steering wheel), it will attempt to keep you in the lane by braking the opposite side of the car.

[Malbec 56 Beast]

It is an awesome system, it sure does is best to keep you where you need to be. I also like the brake assist, it was hard for me not to have my foot in the brake but it will stop on a dime if need be.

Andy

[M37xfan]

Mine works best when I am paying attention....

[Ilya]

Brake assist is nice, I used it in NJ when I was living in Newark for work for 2.5 months. Took a day or two to trust it, but as long as there isnt' direct sun into the sensor, it's pretty damn good.

[CRV_33]

My car has the adaptive cruise control as well. I had the cruise control set to 70mph out on the highway. Out of nowhere I got a beeping sound and an alert that the Intelligent Brake Assist (IBA OFF light flashed) was disabled. Turns out a leaf got caught in the sensor causing the system to disengage. I'm glad it wasn't something electrical.

Just be careful at times the system will encounter random false positives. During the day when I have the cruise control, shadows from bridges and overpasses can cause the car to slam on its brake for second but then re-engage the cruise control. The first time it ever happened, scared the crap out of me. LOL

[mazz]

CRV33 i have had adaptive cruse control on every Infiniti since 2006 maybe sooner [i cant remember if it was on my q45's ] i have never ever had the car SLAM ON THE BRAKES for shade or shadows , something is fishy in your system or mine that sounds dangerous , you could get rear ended like that.
i certainly have had low sun in AM disable the system or hard rain or snow do the same but the car just glides does not do a PANIC STOP.

[Wilbursan]

The one time I used the adaptive cruise control it almost immediately started slowing down. I thought something was wrong but it turns out the guy in front of me was going a lot slower than I thought. I changed lanes and off I went. Neat.

I liked the blind sport warning and (I assume) blind spot intervention but for obvious reasons didn't try to test the latter. The lane departure I'm a lot more ambivalent. I think I'd have to turn it off in the city, but highway use was all I ever wanted it for anyway. I didn't like the way it moved the car back into the lane either. Since it's working the brakes you can feel the car drastically slow down as soon as it engages. I don't know why but I didn't expect that. If the cruise was on would it disengage? Would it slow down until it eased up on the bakes? I'd test it myself but I took the car back.

[Ilya]

Used it today in varying degrees of sun and shade and worked perfectly. I love it.

[GMBQ70]

Reviving an older Thread here- but this feature sure came in handy today. Record cold temps in Louisiana today along with icy road conditions, which we rarely have. On my way into work this morning (can’t believe my office as opened) I hit several patches of ice (at low speed) and the car corrected itself very nicely. Honestly the first time this feature has really been needed or been necessary in almost one year of ownership. Certainly made a difference. Great feature.

[EdBwoy]

Not to split hairs GMB, but I am curious if that was not some other safety feature in the alphabet soup. Were you driving with cruise control set and the DCA system turned on?
There are some interlocks that turn off the intelligent cruise control and tire slip on the first patch of ice would be one (temps below freezing should also be another trigger); I need to read more on what the criteria for the LDP are.

Maybe what you experienced was probably the VDC system working in conjunction with the ABS - the car should do that even with the cruise control or lane departure prevention turned off.

[GMBQ70]

Not to split hairs GMB, but I am curious if that was not some other safety feature in the alphabet soup. Were you driving with cruise control set and the DCA system turned on?

Maybe what you experienced was probably the VDC system working in conjunction with the ABS - the car should do that even with the cruise control or lane departure prevention turned off.

Cruise control was not on, and the DCA system was not as well. I was at low speed, so no need for cruise control.
As stated in the original post-We rarely experience icy roads in South Louisiana, so everyone around me was exercising extreme caution and traveling at a low rate of speed.
Regardless of what system kicked in, it was nice to have this feature.