Why doesn't FSD hug the left side of the right lane?

[momo3605]

On a street like this below for example, if you're traveling in the right lane, FSD Beta will follow the RED path and cause the car weave in and out of the parked cars on the right. This has been an issue since 10.2, and from what I recall, is NOT an issue when using old AP autosteer on city streets.

Many times it's hard to generalize a situation, but Is there any instance where hugging the left line would not be desired(i.e. following GREEN path)? Im just wondering why this continues to be an issue. Seems like an easy enough fix. Most city streets in Bay Area suburbs are like this, without clear lines or bike lanes on the right side.

 

[jjrandorin]

Many times it's hard to generalize a situation, but Is there any instance where hugging the left line would not be desired?

Any time there is a car next to you in the other lane, or, if talking about the center lane, any time there is a car coming the other way. It would freak out people in the lane next to you if you / your car was "hugging the left lane" when they were there, and they would instinctively move their car toward the left of their lane, possibly even crossing into another lane / center divider, all while cursing at you.

I dont engage at all in most of the "FSD" debates, but "is there any instance where hugging the left lane would not be desired" seems like the answer is clearly "yes, any time there is a car in that lane".

Look at the very first post in the "already existing" thread on this exact topic for what I feel most peoples reaction would be.

FSD Beta hugging left centerline

Wondering if anyone else noticed the Beta hugging the left centerline. I often find myself knocking off FSD because I keep pulling vehicle to the right. Dash display shows obviously vehicle is more toward the left centerline. Also on 2 lane roads I get a pause (reduced speed) as vehicles...

teslamotorsclub.com

 

[momo3605]

Any time there is a car next to you in the other lane, or, if talking about the center lane, any time there is a car coming the other way. It would freak out people in the lane next to you if you / your car was "hugging the left lane" when they were there, and they would instinctively move their car toward the left of their lane, possibly even crossing into another lane / center divider, all while cursing at you.

I dont engage at all in most of the "FSD" debates, but "is there any instance where hugging the left lane would not be desired" seems like the answer is clearly "yes, any time there is a car in that lane".

maybe i'm not asking the question in a clear way. Please let me know if there's a less awkward way to describe what it lol. I'm talking about being in the right lane, next to the parked cars. On the left side of the line, you have cars traveling in the same direction as you. Why would that freak them out?

 

[jjrandorin]

maybe i'm not making myself clear. I'm talking about being in the right lane, next to the parked cars. On the left side of the line, you have cars traveling in the same direction as you. Why would that freak them out?

because your car hugging that lane would push anyone in the lane next to you to the left as well, because it would be perceived as being "too close" if it was cruising at that location without moving over when there was more room.

 

[momo3605]

because your car hugging that lane would push anyone in the lane next to you to the left as well, because it would be perceived as being "too close" if it was cruising at that location without moving over when there was more room.

i just re-uploaded the pic with lines. The current behavior is the RED line, which is entirely incorrect. The car should just go straight following the GREEN line

Look at the very first post in the "already existing" thread on this exact topic for what I feel most peoples reaction would be.

FSD Beta hugging left centerline

Wondering if anyone else noticed the Beta hugging the left centerline. I often find myself knocking off FSD because I keep pulling vehicle to the right. Dash display shows obviously vehicle is more toward the left centerline. Also on 2 lane roads I get a pause (reduced speed) as vehicles...

teslamotorsclub.com

This is a different situation. A bi-directional road, where you're hugging the center line with cars coming towards you on the left.

 

[Raurele]

On freeways it should hug the left line. So at every
Merger you don’t swerve to the middle of 2 when lines disappear. It’s not universal

 

[momo3605]

On freeways it should hug the left line. So at every
Merger you don’t swerve to the middle of 2 when lines disappear. It’s not universal

Yes exactly I agree, it should hug the left line, even on the freeway, (which AP has also gotten a lot better at). It seems like in most cases, hugging left line is the best

 

[johnm]

Because someone once used the phrase "lane centering."

Really, it seems like they have put very little thought into where in the lane the car should be. For example:

• Road with no lane lines.
• Right turns without a painted turn lane.
• Two lane undivided highways with 12 foot wide empty shoulders.
• One way roads with parking on one side of the road.
• ...

 

[RTPEV]

Agree with the OP and other similar sentiments in this thread. Probably "hugging" was the wrong word to use, but the car should recognize what appears to be a "wide" lane and correctly position itself within it, rather than "centering", which is usually the wrong thing to do. The main concern I have with this behavior is on highways with unmarked on-ramps (as @Raurele mentioned). In some states (Virginia) this is a serious problem as my car will swerve to the right at the end of the merge lane (as if I was getting ready to pull onto the shoulder) and then swerve violently back to the right lane. Now THAT behavior is what will worry drivers in the left lane of the highway that are passing you. My wife's ID.4 lane assist has no problem at all behaving naturally at these on-ramps. Extremely disappointed that this hasn't been addressed, but I figure that California on-ramps must be well marked so the AP engineers don't experience this behavior and thus it doesn't get addressed.

On a related note, my neighborhood roads are normal sized 2 lane roads, but have no centerline or shoulder lines. Again, the car wants to center itself meaning it's driving down the middle of the road. Granted, it does the right thing when there is an oncoming vehicle and moves to the right, but in the meantime, the oncoming car is wondering why I am driving down the middle of the street and justifiably pulls to the very edge of the road and sometimes even stops. And when making a left turn, it cuts the corner so much that I am fully in the wrong lane in the middle of the turn. For this reason I will not use FSD beta in my neighborhood. Again, I don't see why the car cannot detect that the "lane" it sees is significantly wider than a normal lane and determine that it should "hug" the right. Granted, we're talking about "hugging" the left in one scenario vs. "hugging" the right, but the car should be able to determine whether it's a highway scenario (sees lane markings on the left) versus neighborhood road (no lane markings at all).

 

[momo3605]

the car should be able to determine whether it's a highway scenario (sees lane markings on the left) versus neighborhood road (no lane markings at all).

Yea, or in my OP…basically any situation where You have lane markings on the left and no lane markings on the right, the car should generally always stay near the lane markings (not hug if that’s the wrong word).

Of course in a situation with no lane markings, maybe it should default to staying to the right.

 

[beachmiles]

This is currently one of my top issues with FSD with the other being the car always starts slowing down way too late.

Most roads in my area have parallel parking on both sides of the street and unmarked bike lanes and/or unmarked right turn lanes making the right lane a much larger lane / double wide lane / 2 lanes in 1. The Tesla always wants to take up this entire larger right lane or even err on centering itself closer to the right of this large lane when I'm trying to go straight.

If a parked car on the street starts pulling out / a parked car opens its door without looking, or a bike jets out into the unmarked bike lane this is not mellow. Or if a car wants to use a unmarked right turn lane when I'm coming to a stop sign it can't because the Tesla is hogging the large double wide right lane.

 

[drtimhill]

maybe i'm not asking the question in a clear way. Please let me know if there's a less awkward way to describe what it lol. I'm talking about being in the right lane, next to the parked cars. On the left side of the line, you have cars traveling in the same direction as you. Why would that freak them out?

I get what you are saying .. and I've noticed this too. It's not really about "hugging" the left part of the lane, its really the car extrapolating that there should be an invisible (assumed) lane line on the right and it should then center in this imputed lane. This would still leave plenty of clearance to the left but also stop the car weaving all over the place as it encounters parked cars. Basically, what a human would be doing.

 

[FLMan]

my car will swerve to the right at the end of the merge lane (as if I was getting ready to pull onto the shoulder) and then swerve violently back to the right lane.

I'm not on beta, but my FSD highway does this (although not violently) but it's still annoying to drift "off the road" making the person on your tail think they can pass and all of a sudden you're moving back into the lane. The only thing I can think of is that maybe it's trying to cut off people from merging in - even when nobody is there.

 

[RTPEV]

I'm not on beta, but my FSD highway does this (although not violently) but it's still annoying to drift "off the road" making the person on your tail think they can pass and all of a sudden you're moving back into the lane. The only thing I can think of is that maybe it's trying to cut off people from merging in - even when nobody is there.

The "violence" of it depends entirely on the geometry of the road/on-ramp and markings (or lack thereof). Usually it's not that severe, but occasionally you have a very wide on-ramp on a slight right curve. The car attempts to center itself in what it thinks is a super wide lane (but is really the end of the on-ramp and the normal travel lane, thanks to lack of markings on the on-ramp). When the car actually does reach the true end of the on-ramp, it swings pretty quickly back into the travel lane. Along the east coast, I've found Virginia's on ramps to be the worst by far (not necessarily along I-95, but on I-81 and parts of US-29). Pennsylvania has a few exits that are problematic as well.

 

[Raurele]

The "violence" of it depends entirely on the geometry of the road/on-ramp and markings (or lack thereof). Usually it's not that severe, but occasionally you have a very wide on-ramp on a slight right curve. The car attempts to center itself in what it thinks is a super wide lane (but is really the end of the on-ramp and the normal travel lane, thanks to lack of markings on the on-ramp). When the car actually does reach the true end of the on-ramp, it swings pretty quickly back into the travel lane. Along the east coast, I've found Virginia's on ramps to be the worst by far (not necessarily along I-95, but on I-81 and parts of US-29). Pennsylvania has a few exits that are problematic as well.

Honestly, these are points where you should just know your car, and know the limits of AP. If you're unsure if it will take the turn in a way youre comfortable with, take over well before that moment. Be vigilant. This is not an autonomous vehicle, and it doesn't claim to be.

 

[RTPEV]

Honestly, these are points where you should just know your car, and know the limits of AP. If you're unsure if it will take the turn in a way youre comfortable with, take over well before that moment. Be vigilant. This is not an autonomous vehicle, and it doesn't claim to be.

Agreed. I am well aware of where the problem areas are, so I can take steps to safely navigate them.

The problem is that now I need to constantly take the car in and out of AP at each exit ramp (because the car keeps insisting on getting into the passing lane because it thinks that it's in the exit lane even though the exit lane hasn't quite started -- this is more of an NC phenomenon, but it happens in other states as well), and at on-ramps in states that don't have adequate markings (to avoid the car swerving to the right and then back to the left). This significantly reduces the value of AP (at least in my opinion, and we're not even talking about FSD beta yet--it's even worse there!) The lane keep assist on my wife's ID.4 has no problem with this, as it appropriately "hugs" the left side of the lane at on-ramps.

 

[ChrisMPK]

This is my #1 problem with FSD and NOA on city roads before it. Just hug the left lane line, don't drive in the parking lane like an idiot. This seems like an easily solveable set of circumstances that have received zero attention over the last couple years.

 

[tps5352]

In some areas, entrance-ramp acceleration lanes entering a limited-access highway (e.g., interstate freeway) on the right are differentiated with a dashed line. (Something like the diagram directly below. Tesla with FSD Beta in green; other cars in blue.)

​

My car with FSD Beta activated tends to stay in the right-hand lane (if that is where I happen to be), where it belongs.

But (for various reasons) there can be no, or only a very short, line separating the on-ramp acceleration lane from the right-hand lane.

​

In this case, unless I prevent it I find that my car tends to drift to the right (searching for a right-side lane marker, I assume).

​

Although I have not had a problem so far, this could be dangerous (what with rapidly accelerating cars entering from behind). I have not figured out how to stop it, other than to arrest control from FSD and steer the car back into the right-hand lane (or stay out of the right-hand lane except to exit).

I believe I am reiterating what others have already described, above.

Since left-hand entrances are less common, I guess I would prefer the car to orient itself within a lane based on a left-hand lane marker.

 

[RTPEV]

In some areas, entrance-ramp acceleration lanes entering a limited-access highway (e.g., interstate freeway) on the right are differentiated with a dashed line. (Something like the diagram directly below. Tesla with FSD Beta in green; other cars in blue.)

View attachment 775625​

My car with FSD Beta activated tends to stay in the right-hand lane (if that is where I happen to be), where it belongs.

But (for various reasons) there can be no, or only a very short, line separating the on-ramp acceleration lane from the right-hand lane.

View attachment 775626​

In this case, unless I prevent it I find that my car tends to drift to the right (searching for a right-side lane marker, I assume).

View attachment 775627​

Although I have not had a problem so far, this could be dangerous (what with rapidly accelerating cars entering from behind). I have not figured out how to stop it, other than to arrest control from FSD and steer the car back into the right-hand lane (or stay out of the right-hand lane except to exit).

I believe I am reiterating what others have already described, above.

Since left-hand entrances are less common, I guess I would prefer the car to orient itself within a lane based on a left-hand lane marker.

Yes, your pictures illustrate the problem perfectly, except that the car is not trying to search for a right lane marker, but rather just centering itself in what it sees as a very wide lane! The car should be able to detect that the lane is wider than "normal" and even be aware that it is at an on-ramp and should favor the left lane marker.

Also, this really doesn't have anything to do with FSD Beta -- this is standard Autopilot behavior (since it's on a limited access highway). And not only is it dangerous because it may be cutting off the entering vehicle, but as I said previously, with certain road geometries, the car will sometimes swerve pretty rapidly back into the travel lane at the end of the on-ramp, which no doubt is concerning to vehicles in the passing lane.

 

[QUBO]

I didn't want to start a new thread, and don't want to co-opt this one, but here goes. I have AP1 and only use it on two lane divided highways. With clear lane markings, but going straight over a slight hill, it will decide it needs to swerve left or right because it has briefly lost the lane markings at the top of the very slight rise. In these situations, the car doesn't beep or otherwise indicate that autosteer is unavailable.

My question, similar to the OPs, is why not use the last one second of driving information to continue until it regains the highway line markings? This seems like a very easy software adjustment, i.e. if you lose the lane marking just keep doing what you've been doing, which is usually just keep going straight on the two lane divided highway.