Guess 5-digit mileage would come eventually...
09-01-14, 02:30 PM
#16
When you guys get dash cams, try out your DRCC in moderate traffic on a local freeway. Then, check out your recorded videos. They'll be full of lane-jumpers and slowpokes. Guaranteed.
It doesn't really matter what the CAUSE of the mismatch between design and reality is, does it? I'm not blaming anyone here; I'm simply reporting my extensive experience with ACC (generic term "adaptive cruise control") of which DRCC is a typical implementation. Additionally, I've researched recent and current studies on ACC and V2V (vehicle to vehicle communication) issues, and I have viewed many online videos that clearly show evidence of the problems I have described. The studies support both the reasonability and safety of a 2-second or more gap between vehicles AND the practical impossibility of maintaining such a gap in traffic as routinely encountered in the USA and around the world.
For a good video showing the effects I've described see the one linked below (skip first 6 minutes or so). As I recall, there are at least 6 successful lane-jumpers and 2 scary attempts that resulted in near accidents (all in 6 or 7 minutes!). Whether you wish to blame the near misses on the bad behavior of the other drivers is irrelevant. Had there been NO gap created by ACC, they would never have attempted to jump lanes in front of the subject vehicle. Also, I believe the original leading vehicle was a slowpoke since both left and right lanes continually pass the camera car. Do you guys see something different?
It doesn't really matter what the CAUSE of the mismatch between design and reality is, does it? I'm not blaming anyone here; I'm simply reporting my extensive experience with ACC (generic term "adaptive cruise control") of which DRCC is a typical implementation. Additionally, I've researched recent and current studies on ACC and V2V (vehicle to vehicle communication) issues, and I have viewed many online videos that clearly show evidence of the problems I have described. The studies support both the reasonability and safety of a 2-second or more gap between vehicles AND the practical impossibility of maintaining such a gap in traffic as routinely encountered in the USA and around the world.
For a good video showing the effects I've described see the one linked below (skip first 6 minutes or so). As I recall, there are at least 6 successful lane-jumpers and 2 scary attempts that resulted in near accidents (all in 6 or 7 minutes!). Whether you wish to blame the near misses on the bad behavior of the other drivers is irrelevant. Had there been NO gap created by ACC, they would never have attempted to jump lanes in front of the subject vehicle. Also, I believe the original leading vehicle was a slowpoke since both left and right lanes continually pass the camera car. Do you guys see something different?
09-01-14, 02:48 PM
#17
Racer
Thread Starter
I'll take a look at the video, though I've seen my share of slowpokes, lane jumpers and other idiots on the road. They abound around here.
My point, which I did not make clearly, was that the shortest gap setting actually seemed adequate and appropriate to me at highway speed, and if anyone jumps in front of you (with or without DRCC), it is not DRCC's fault in that particular case. Of course, there are the questions of reaction time (DRCC vs. driver), and the effective "doubling" of the gap, and I do not dispute those. I would, however, argue that at highway speed, this is not substantially different than what you would do as a prudent driver.
At lower speeds and under other traffic conditions, I could see the lane-jumper and slowpoke effects joining forces and propagating throughout the system and screwing things up, but I'm not sure I would be using DRCC under most of those conditions. Having said that, this is why I want to look at the video you shared to watch what you are describing "in action".
My point, which I did not make clearly, was that the shortest gap setting actually seemed adequate and appropriate to me at highway speed, and if anyone jumps in front of you (with or without DRCC), it is not DRCC's fault in that particular case. Of course, there are the questions of reaction time (DRCC vs. driver), and the effective "doubling" of the gap, and I do not dispute those. I would, however, argue that at highway speed, this is not substantially different than what you would do as a prudent driver.
At lower speeds and under other traffic conditions, I could see the lane-jumper and slowpoke effects joining forces and propagating throughout the system and screwing things up, but I'm not sure I would be using DRCC under most of those conditions. Having said that, this is why I want to look at the video you shared to watch what you are describing "in action".
09-01-14, 03:27 PM
#18
An open mind is a wonderful thing - seriously.
You may wish to peruse Fig. 1 in the PDF paper attached to this message. The paper is full of palaver about control system theory and basically proposes a non-linear inter-vehicle "gap" relative to vehicle speed. Forget all that as Fig. 1 lays out the entire story: 2-second linear gap maintained at all speeds (typical of current ACC systems), the authors' non-linear proposal, and, MOST IMPORTANT, real-world gap observations from freeways around Paris, France. Note the linearity of the real world "gap." It remains almost constant at all vehicle speeds and works out to LESS THAN ONE SECOND as best I can tell. So, is there ANY hope for effective ACC systems in the real world? According to U.S. NHTSA, V2V must first be mandated and then we just have to wait 15 or 20 years until a critical mass of cars can talk to each other and remove the human from the control loop.
You may wish to peruse Fig. 1 in the PDF paper attached to this message. The paper is full of palaver about control system theory and basically proposes a non-linear inter-vehicle "gap" relative to vehicle speed. Forget all that as Fig. 1 lays out the entire story: 2-second linear gap maintained at all speeds (typical of current ACC systems), the authors' non-linear proposal, and, MOST IMPORTANT, real-world gap observations from freeways around Paris, France. Note the linearity of the real world "gap." It remains almost constant at all vehicle speeds and works out to LESS THAN ONE SECOND as best I can tell. So, is there ANY hope for effective ACC systems in the real world? According to U.S. NHTSA, V2V must first be mandated and then we just have to wait 15 or 20 years until a critical mass of cars can talk to each other and remove the human from the control loop.
09-01-14, 05:19 PM
#19
Wow, radar cruise debate takes off!!!! Comments on the video:
1. Yes, in stop and go traffics like in the 1st several minutes of the video, I wouldn't even think of using radar cruise.
2. Watching the video that last several minutes at a good speed, I didn't see a problem. People will cut in line just like they do at the fair. Nothing you can do about that. I guess you can tailgate and play chicken with your 2ton car.
3. I still argue that maintaining a safe distance is the right thing to do. If someone cuts in front of you, then so be it. Too many people tail gate.
4. The reality of future road driving are systems like this. If everyone had radar cruise and lane detection systems, we could drive without thinking. It's coming, so get used to it. I went to school at Va. Tech and we discussed this 20 years ago in my transportation engineering class.
5. Last thing, the video music about out me to sleep.
Just my 2 cents from my education.
1. Yes, in stop and go traffics like in the 1st several minutes of the video, I wouldn't even think of using radar cruise.
2. Watching the video that last several minutes at a good speed, I didn't see a problem. People will cut in line just like they do at the fair. Nothing you can do about that. I guess you can tailgate and play chicken with your 2ton car.
3. I still argue that maintaining a safe distance is the right thing to do. If someone cuts in front of you, then so be it. Too many people tail gate.
4. The reality of future road driving are systems like this. If everyone had radar cruise and lane detection systems, we could drive without thinking. It's coming, so get used to it. I went to school at Va. Tech and we discussed this 20 years ago in my transportation engineering class.
5. Last thing, the video music about out me to sleep.
Just my 2 cents from my education.
09-01-14, 05:25 PM
#20
FWIW, I recall playing chicken twice in my life. Once a friend of mine was coming at me in a car and came into my lane. I then switched to his lane. We both laughed later. However, 25 years late and wiser, I'm sure we both agree it was foolish. Other time was with my wife. Sorry, I won't tell you the details of that game. Needless to say, we've been together for 16 years now and have 3 wonderful children. Later!!
09-01-14, 05:30 PM
#21
I've been reading and man I want this feature.... Sure there are problems but, I bet it's better than I do now in my 2001 LS430...
On cruse, 65-70, get cut in front of, flip the switch to coast, then as they speed up, use the switch to speed me up again....and so on and so on....on my hour commute..
Makes me kind of regret I didn't hold out for a UL 430....as I was thinking at the time to wait but, the car I had and the price I got about 10 years ago (yea, I know it's about time), I could not pass up.
My wife is like, if it Ain't broke, don't replace it
On cruse, 65-70, get cut in front of, flip the switch to coast, then as they speed up, use the switch to speed me up again....and so on and so on....on my hour commute..
Makes me kind of regret I didn't hold out for a UL 430....as I was thinking at the time to wait but, the car I had and the price I got about 10 years ago (yea, I know it's about time), I could not pass up.
My wife is like, if it Ain't broke, don't replace it
09-01-14, 06:57 PM
#22
I've been reading and man I want this feature.... Sure there are problems but, I bet it's better than I do now in my 2001 LS430...
On cruse, 65-70, get cut in front of, flip the switch to coast, then as they speed up, use the switch to speed me up again....and so on and so on....on my hour commute..
Makes me kind of regret I didn't hold out for a UL 430....as I was thinking at the time to wait but, the car I had and the price I got about 10 years ago (yea, I know it's about time), I could not pass up.
My wife is like, if it Ain't broke, don't replace it
On cruse, 65-70, get cut in front of, flip the switch to coast, then as they speed up, use the switch to speed me up again....and so on and so on....on my hour commute..
Makes me kind of regret I didn't hold out for a UL 430....as I was thinking at the time to wait but, the car I had and the price I got about 10 years ago (yea, I know it's about time), I could not pass up.
My wife is like, if it Ain't broke, don't replace it
09-01-14, 07:45 PM
#23
I promise I will take better ones, but here are a few phone pics. This was the one thing that made me comfortable with the light interior. The entire dash is black as are the lower half and some of the upper half of the doors. It appears to be a 600h only feature, but I've never gotten confirmation, plus I've seen this same interior in a 600h without the black.
09-01-14, 07:57 PM
#24
09-01-14, 08:42 PM
#25
Wow, radar cruise debate takes off!!!! Comments on the video:
1. Yes, in stop and go traffics like in the 1st several minutes of the video, I wouldn't even think of using radar cruise.
2. Watching the video that last several minutes at a good speed, I didn't see a problem. People will cut in line just like they do at the fair. Nothing you can do about that. I guess you can tailgate and play chicken with your 2ton car.
3. I still argue that maintaining a safe distance is the right thing to do. If someone cuts in front of you, then so be it. Too many people tail gate.
4. The reality of future road driving are systems like this. If everyone had radar cruise and lane detection systems, we could drive without thinking. It's coming, so get used to it. I went to school at Va. Tech and we discussed this 20 years ago in my transportation engineering class.
5. Last thing, the video music about out me to sleep.
Just my 2 cents from my education.
1. Yes, in stop and go traffics like in the 1st several minutes of the video, I wouldn't even think of using radar cruise.
2. Watching the video that last several minutes at a good speed, I didn't see a problem. People will cut in line just like they do at the fair. Nothing you can do about that. I guess you can tailgate and play chicken with your 2ton car.
3. I still argue that maintaining a safe distance is the right thing to do. If someone cuts in front of you, then so be it. Too many people tail gate.
4. The reality of future road driving are systems like this. If everyone had radar cruise and lane detection systems, we could drive without thinking. It's coming, so get used to it. I went to school at Va. Tech and we discussed this 20 years ago in my transportation engineering class.
5. Last thing, the video music about out me to sleep.
Just my 2 cents from my education.
2. and 3. People only cut into a gap when there is a gap for them to cut into. A 2-second gap at 60mph is about 10 car-lengths. This is a flashing, illuminated, neon sign for anyone to "cut" in front of you. The DRCC's response to this invasion has already been discussed. The definition of "safe" is somewhat situational, don't you agree? What of all those French drivers and your own experience on U.S. freeways in moderate traffic? TEN car-lengths? I defy you to find ANYONE able to "maintain" such a "safe distance." I, and the majority of drivers I see every day, don't consider 4 car-lengths at 65 or 70mph either unsafe OR tailgating. Obviously, others have different views. But those opinions have no PRACTICAL weight. Since other drivers will cut into any gap of greater than 4 or 5 car-lengths, it is IMPOSSIBLE for you to maintain what you say is a "safe" following distance. You'll just keep slowing down to recreate your desired gap and another lane jumper will jump in to fill it. And you'll slow down some more - just like DRCC!
4. The reality is all about V2V as just proposed last week by NHTSA. Read the 300+ page report and you'll see EXACTLY where things are going. No need for guessing at all.
5. Agree on the music...zzz...
Last edited by williakz; 09-01-14 at 08:46 PM.
09-01-14, 08:43 PM
#26
Laser/radar cruise
What is the big deal about something being new about this. It was a $600 option on a 2006 Toyota Avalon Limited that I used to own. It's one big failing is that is does not function in rain or snow. The water screws up the system and shuts it down.
09-02-14, 08:04 AM
#27
The "big deal" is the evolution of the function from its early days until now (and its future evolution as being developed by government and manufacturers). The "old" ACC cut out at speeds below some minimum (around 25-30mph as I recall). This "feature" was designed to prevent drivers from using the function in low-speed, non-freeway (surface road), stop-and-go applications. However, it quickly became apparent that the unintended consequence of the cut-out was to lull drivers into a false sense of security that their vehicles would slow down in slowing freeway traffic when, in fact, the system would abruptly cut out and deliver a shocked, screaming driver frantically trying to jam on the brakes to avoid rear-ending the suddenly stopped vehicle ahead of him. Oops!
So manufacturers subsequently removed the cut-out feature, allowing vehicles to go all the way to standstill (zero speed) and then resume their setpoints at the touch of a button/pedal or even automatically after a time delay. To cover the liability they sought to avoid the first time around, car makers gently suggested that drivers use the function ONLY on "expressways" and ONLY in light to moderate traffic conditions (as the 2013 LS460 advises). Of course, drivers routinely use the function, AS THEY SHOULD, in non-freeway applications where - given reasonable gap settings - it makes tedious surface road driving much more tolerable, especially in high traffic conditions.
So, that's what "new." Where things go from here and at what rate they develop is subject to the confluence of government regulation, manufacturer ingenuity, legal liability, and customer preference.
So manufacturers subsequently removed the cut-out feature, allowing vehicles to go all the way to standstill (zero speed) and then resume their setpoints at the touch of a button/pedal or even automatically after a time delay. To cover the liability they sought to avoid the first time around, car makers gently suggested that drivers use the function ONLY on "expressways" and ONLY in light to moderate traffic conditions (as the 2013 LS460 advises). Of course, drivers routinely use the function, AS THEY SHOULD, in non-freeway applications where - given reasonable gap settings - it makes tedious surface road driving much more tolerable, especially in high traffic conditions.
So, that's what "new." Where things go from here and at what rate they develop is subject to the confluence of government regulation, manufacturer ingenuity, legal liability, and customer preference.
Last edited by williakz; 09-02-14 at 08:42 AM.
09-02-14, 09:30 PM
#28
DRCC isn't the "end all" solution - it's perfect for certain situations.
Example: I live in the Columbus area - took my son to the NBA Eastern conference finals game 1 in Indianapolis.
The entire drive is the two lane I-70 - about 180 miles. Set the cruise up in the low 80's - several semis were slowly passing each other. Left hand lane truck was going 66 MPH and the right 65. It took miles for each one of them to pass each other - but eventually they did, and the cruise held a steady distance and people weren't cutting in front of me. As soon as the fast lane truck got over, the DRCC kicked in and sped me back up to cruising speed.
No, it isn't for heavy traffic, and yes people do cut in front of you sometimes. But, think of the lawsuits Lexus would face if it allowed one to ride 20 feet behind someone @ 80 MPH. Again, it's ideal for higher light to moderate traffic on the freeway - I'll pick a car that has this feature over one that doesn't 100 out of 100 times.
If it saves me from a wreck even once with someone cutting in front of me and instantly hitting their brakes all the better.
Example: I live in the Columbus area - took my son to the NBA Eastern conference finals game 1 in Indianapolis.
The entire drive is the two lane I-70 - about 180 miles. Set the cruise up in the low 80's - several semis were slowly passing each other. Left hand lane truck was going 66 MPH and the right 65. It took miles for each one of them to pass each other - but eventually they did, and the cruise held a steady distance and people weren't cutting in front of me. As soon as the fast lane truck got over, the DRCC kicked in and sped me back up to cruising speed.
No, it isn't for heavy traffic, and yes people do cut in front of you sometimes. But, think of the lawsuits Lexus would face if it allowed one to ride 20 feet behind someone @ 80 MPH. Again, it's ideal for higher light to moderate traffic on the freeway - I'll pick a car that has this feature over one that doesn't 100 out of 100 times.
If it saves me from a wreck even once with someone cutting in front of me and instantly hitting their brakes all the better.
09-03-14, 08:23 AM
#29
[
QED
I'll post some of my own videos soon showing just how rarely the "certain situations" needed for "perfect" DRCC operation occur in comparison with the dreary routine of lane jumping, slow-poking, and lawsuit-reduction during NORMAL system operation.
I'll post some of my own videos soon showing just how rarely the "certain situations" needed for "perfect" DRCC operation occur in comparison with the dreary routine of lane jumping, slow-poking, and lawsuit-reduction during NORMAL system operation.
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lexusis305
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11-12-10 10:55 AM