Self Driving Car thread

[M. Jones]

Alamout[/url]":30q6ipmh]That process would take many decades to happen organically--longer than self-driving cars will exist, perhaps. Unless we develop revolutionary advances in both the cost and time of construction projects. Societies and governments need to cause this amount of change--markets aren't going to do it on their own, not at a useful timescale.

This misperception explains your biases, at least.

I can't think of too many times when governments reacted to market needs faster than markets did. Free societies are markets. Here you're talking about taking advantage of technology to increase efficiency and decrease costs. Normally the action of governments is to retard efficiency for political reasons -- jobs, incumbent financial interests, populist appeal.

 

[M. Jones]

Pont[/url]":3g82pj0u]
I really think self-driving taxis will be the biggest, most profound change brought on by self-driving car technology.

They're basically PRT that utilises existing infrastructure, and as such were predicted in these forums to be the eschaton of mass transit.

 

[redleader]

Alamout[/url]":27v5jl99]

redleader[/url]":27v5jl99]

Alamout[/url]":27v5jl99]In fact you can do it much better: no matter how good self-driving cars get, they won't be able to match the passenger density of a train.

In terms of density per sq km, this is probably not true. You cannot fit all that many subway trains into a square km because you can't realistically build all that many subway tubes. Individual trains can hold enormous numbers of people, but the supporting infrastructure needed to operate them probably more than balances out this advantage.

I don't follow this at all. You can't fit all that many cars into a square km either, self-driving or not.

I don't think you understood my post. I'm not saying infinite numbers of cars can occupy a volume. I'm just pointing out that the transport capacity per unit of area tends to be tremendously higher for roads than for trains because of the practical challenges of fitting a very large number of trains per area (extreme cost, difficulty of making overlapping subway tunnels, routing around building foundations, need for relatively large gaps between adjacent trains per tunnel, space used for stations, etc). For this reason, even in dense cities with extensive train systems, the road capacity of the city is generally far higher than the rail capacity.

Alamout[/url]":27v5jl99]
Subways routinely handle tens of thousands of passengers per hour.

Yes, but this is actually quite small relative to total city capacity because that subway tunnel serves an enormous area with many thousands of roads. A city with even a moderately comprehensive bus system for instance will typically match or even exceed the subway ridership with buses alone. Nevermind that the vast majority of road traffic is not buses.

Alamout[/url]":27v5jl99]
I'm all in favor of self-driving cars and I think they'll be great. But they're not a replacement for a real rapid transit system, and they're certainly not an excuse to ignore rapid transit until some future technology is around.

I don't think anyone is saying that public transit is obsolete?

Alamout[/url]":27v5jl99]
We don't need new technological solutions. We need politicians and voters that care about the problem.

Yes we do. While I understand that you like trains, they have extreme cost issues and more moderate issues with transit time and capacity. Furthermore, as a city becomes larger, these issues become more acute because of the difficulty of expanding capacity. If voters cared more about transmit, that would be great, but it won't bend a cost curve.

 

[redleader]

Techie_Jim[/url]":2jbco0p2]LIDAR acts as the autopilot's eyes and it's a neat implementation they have for it now. Will each and every car using LIDAR degrade everyone's fidelity?

No, there are essentially no crosstalk issues with LIDAR. However, lets be clear, its not even certain that lidar will be the technology of choice. 60GHz microwave is probably cheaper and equally as good as optical because you can use electronic beamforming whereas lidar must be mechanically scanned or have multiple fixed emitters/detectors. If you want cars very close to each other, a single 360 degree phased array (or 2 180 arrays fore and aft) are much faster than a galvo scanned optical beam and certainly cheaper than many lidar beams.

Techie_Jim[/url]":2jbco0p2]
Not sure if LIDAR is affected by other LIDAR - is there a potential that mine will 'blind' yours, even unintentionally?

Not really.

Techie_Jim[/url]":2jbco0p2]
Also, LIDAR is able to see general shapes so it can possibly differentiate between a pedestrian, another car, a van/truck, a building, etc. Will it see the flashers on the ambulance behind me and pull over accordingly; recognize the flashers and hand control back for me to handle?

LIDAR is optical radar. It doesn't see emission other than its own being reflected back to it (by design). Generally techniques like heterodyning are used explicitly to avoid cross talk and interference. If you want to see things like road lights and signs, you will need a CMOS camera for that.

 

[Aatos]

Wonder what the rain/snow limitations for microwave sensors are.

 

[M. Jones]

redleader[/url]":kj4yujen]
No, there are essentially no crosstalk issues with LIDAR. However, lets be clear, its not even certain that lidar will be the technology of choice. 60GHz microwave is probably cheaper and equally as good as optical because you can use electronic beamforming whereas lidar must be mechanically scanned or have multiple fixed emitters/detectors. If you want cars very close to each other, a single 360 degree phased array (or 2 180 arrays fore and aft) are much faster than a galvo scanned optical beam and certainly cheaper than many lidar beams.

Radar must normally be licensed, with the FCC. 60GHz is unlicensed, but mostly so because it's severely attenuated by resonance with atmospheric oxygen, and thus of severely limited range. Rain fade is a problem with all EHF spectrum, according to Wikipedia.

 

[Alamout]

redleader[/url]":zb3dk5z5]I don't think you understood my post. I'm not saying infinite numbers of cars can occupy a volume. I'm just pointing out that the transport capacity per unit of area tends to be tremendously higher for roads than for trains because of the practical challenges of fitting a very large number of trains per area (extreme cost, difficulty of making overlapping subway tunnels, routing around building foundations, need for relatively large gaps between adjacent trains per tunnel, space used for stations, etc). For this reason, even in dense cities with extensive train systems, the road capacity of the city is generally far higher than the rail capacity.

I see what you're saying now, but I think you worded it poorly--roads never have a higher capacity per unit area of infrastructure. They might manage higher capacity over a general area given some cost constraints, but that's a different metric. I (mis)interpreted "density per square km" to be referring to the first metric, not the second.

For a given square kilometer, building a train to it is massively better than building a highway there. The problem--and the point you were making, which I get--is that you can't build a train to serve every square kilometer. But the limiting factor there is cost (specifically, cost that doesn't scale linearly with increased capacity), not capacity/area.

The reason that the road capacity of a dense city is higher than its rail capacity is because a huge proportion of the city's area is used on roads (and tons of parking, but in the autonomous-car future we can get rid of some of that parking). In terms of capacity/area-of-transit-infrastructure, rail is clearly better, and that doesn't really change with self-driving cars.

Yes, but this is actually quite small relative to total city capacity because that subway tunnel serves an enormous area with many thousands of roads. A city with even a moderately comprehensive bus system for instance will typically match or even exceed the subway ridership with buses alone. Nevermind that the vast majority of road traffic is not buses.

Sure, and buses (self-driving or not) are much higher-capacity than self-driving cars. I like buses just fine--I'm advocating for mass transit in general, not specifically trains. Trains just represent one end of the (currently available) spectrum. Very high initial investment gets you very high efficiency and capacity, and allows for high population density.

Subway ridership isn't the same as subway capacity, for what it's worth. An underused subway is akin to an empty highway--maybe a failure in city planning, or perhaps overbuilding for future growth.

Honestly I'm not really sure what we're arguing about at this point. A system of thousands of roads and hundreds of buses will have a higher transit capacity than some small number of subway lines, sure. Those roads manage such a high capacity by taking up a lot of space, and they don't come all that cheaply either.

I don't think anyone is saying that public transit is obsolete?

I don't know. In mass-transit threads there is often a post or two that brings up self-driving cars as if they obviate the need for investment in transit infrastructure. In this thread, there seemed to be the sentiment that self-driving cars allow for all these magical changes in our society--the point I was trying to make is that those changes are possible now, and the primary barrier is cultural rather than technological. We shouldn't punt on trying to make these changes just because we lack some particular technology.

Shorter version: if you want a car-free or low-car-usage society, you should be advocating for lots of mass transit now, and self-driving cars in the future, rather than just waiting for self-driving cars.

Yes we do. While I understand that you like trains, they have extreme cost issues and more moderate issues with transit time and capacity. Furthermore, as a city becomes larger, these issues become more acute because of the difficulty of expanding capacity. If voters cared more about transmit, that would be great, but it won't bend a cost curve.

The cost issues are mostly a matter of sticker shock--infrastructure projects need to be evaluated on decade-long timeframes, and these projects look fine with that perspective*. Transit planning operates on a similar timeframe, in that they must try to project usage needs decades in advance, to try to head off the need to expand capacity. Really, filling your transit system to capacity is a sign that it was a fantastic investment, but people seem to forget that and have another round of sticker shock when asked to make a similar investment again.

Expanding road capacity in a dense area is no picnic either. In fact it can be even more difficult because roads have lower efficiency per unit area and you start out with so many of them--adding a highway lane is a trivial capacity increase at a huge cost, while adding a rail line is a large increase at a huge cost.

* Excluding cases of gross mismanagement, to which highways are just as vulnerable.

 

[dh87]

ChrisG[/url]":s07z0mnw]
Actually, I think much of this thread is pure fantasy. Self-driving cars aren't going to start appearing, on-roads, in significant numbers, for many decades yet.

From NHK:

Nissan to test self-drive car on public roads

...

Nissan is hoping to put the self-driving car on sale in 2020.

6 years might be a bit optimistic, but "decades" is very likely wrong.

I think that a huge benefit of s-d cars will be their fuel economy. There's no reason for an s-d car to go from 0 to 60 at any appreciable rate. In fact, if I'm reading the newspaper or taking a nap, I'd prefer 0 to 60 to be as gentle as possible. Hence, engines can all be low-power hybrids or electrics. That's how all the carmakers are planning to meet the 2025 standard of 55mpg fleet average.

 

[Alamout]

M. Jones[/url]":3u1fhgre]This misperception explains your biases, at least.

I can't think of too many times when governments reacted to market needs faster than markets did.

And you talk about biases.

Government action doesn't often react to market needs, but governments have the resources to transform existing markets or create entirely new ones, by making investments that are not profitable over the short term or are only beneficial for society as a whole rather than for some investment.

Like, say, mass transit projects.

Free societies are markets. Here you're talking about taking advantage of technology to increase efficiency and decrease costs. Normally the action of governments is to retard efficiency for political reasons -- jobs, incumbent financial interests, populist appeal.

The point I was making in the quoted portion was just that urban renewal is very slow--just like it takes many years for all the cars on the road to get replaced, it takes many decades for buildings to get replaced, so it can take a city a century to remake itself to react to new technology. Consider how many buildings in a given city were built before World War I. Barring a natural disaster, cities are very slow to change.

Urban renewal is not a free market anyway. Hardly anything is a free market of the kind you imagine, which is why the "markets will solve it" philosophy is so very wrong so very often.

 

[Stainless]

dh87[/url]":10s53qtg]

ChrisG[/url]":10s53qtg]
Actually, I think much of this thread is pure fantasy. Self-driving cars aren't going to start appearing, on-roads, in significant numbers, for many decades yet.

From NHK:

Nissan to test self-drive car on public roads

...

Nissan is hoping to put the self-driving car on sale in 2020.

6 years might be a bit optimistic, but "decades" is very likely wrong.

I think that a huge benefit of s-d cars will be their fuel economy. There's no reason for an s-d car to go from 0 to 60 at any appreciable rate. In fact, if I'm reading the newspaper or taking a nap, I'd prefer 0 to 60 to be as gentle as possible. Hence, engines can all be low-power hybrids or electrics. That's how all the carmakers are planning to meet the 2025 standard of 55mpg fleet average.

Eletronic ABS was available in the early 70's - ABS wasn't really widespread in new cars until the early 90's, and that's when the clock really starting running for on the road fleet turn over. For USA the last figure I saw for average car age was a bit over 10 years.

Self drive isn't cheap and is quite limited in currently available forms - so to see significant numbers (which admittedly is a poorly defined mark) decades is probably not that bad a guess.

 

[ChrisG]

dh87[/url]":1i5gogqq]

ChrisG[/url]":1i5gogqq]
Actually, I think much of this thread is pure fantasy. Self-driving cars aren't going to start appearing, on-roads, in significant numbers, for many decades yet.

From NHK:

Nissan to test self-drive car on public roads

...

Nissan is hoping to put the self-driving car on sale in 2020.

6 years might be a bit optimistic, but "decades" is very likely wrong.

Keyword : "test".

 

[dh87]

ChrisG[/url]":1dphmk6b]

dh87[/url]":1dphmk6b]

ChrisG[/url]":1dphmk6b]
Actually, I think much of this thread is pure fantasy. Self-driving cars aren't going to start appearing, on-roads, in significant numbers, for many decades yet.

From NHK:

Nissan to test self-drive car on public roads

...

Nissan is hoping to put the self-driving car on sale in 2020.

6 years might be a bit optimistic, but "decades" is very likely wrong.

Keyword : "test".

You can focus on "test," and I can focus on "on public roads," and we'll revisit this is 2022 to see whether Nissan's forecast or yours is more accurate.

Edit: It's not just that Nissan is working on this; all the carmakers are working on this, along with several tech companies. That competition will rapidly push progress. The companies have invested in this because they think that the difficulties will be surmounted and any company without a self-driven car will be lost.

 

[wco81]

Here's a column on the state of autonomous cars at various companies:

http://online.wsj.com/article/SB1000142 ... jemAutos_h

Interesting that the FCC has already set aside spectrum for mobile communications, specifically for autonomous cars to communicate to the infrastructure and to other autonomous cars, to fully realize a vision of "sky net" alluded to in the article.

There are different visions though. The head of Toyota USA said ultimately, autonomous cars would be like auto-pilot on planes, where you'd always have a human pilot ready to take over if something happens. However, the column alludes to the fact that auto systems can react much faster than humans can to avoid collisions in certain situations.

Certainly if the co-pilot was in the front seat fiddling with his smart phone or dozing off because he's come to expect the auto-pilot to work, how quickly would he react because the auto-pilot seemed to be directing the car towards a crash?

I think acceptance of the technology would be a great hurdle. This tech would be rolled out first in luxury or premium vehicles, because of the costs of the sensors, computers, etc. But a lot of these marques sell the driving experience, with high-performance suspensions and tires shown off in commercials where professional drivers are speeding around narrow and curving mountain roads.

Will people buy premium cars, and possibly pay more for the sensors and computers, so that they can be passengers in their cars? Presumably, the tech can't be rolled out to more mass-market cars until there's a certain level of acceptance on premium cars, just as air bags, GPS and other features had to migrate from expensive to more affordable cars. They haven't been able to migrate hybrid or EV to mass market cars yet, for instance.

 

[Alamout]

Will people buy premium cars, and possibly pay more for the sensors and computers, so that they can be passengers in their cars?

Sure, plenty of them will. Most premium cars aren't bought because the owner loves to drive. They're more comfortable, and they're status symbols. A self-driving car improves on both of those things.

The ne plus ultra luxury driving experience isn't a Ferrari, it's a luxury car and a chauffeur. With a self-driving car, you get a robotic chauffeur. They'll have no problem selling it in the luxury market.

You can focus on "test," and I can focus on "on public roads," and we'll revisit this is 2022 to see whether Nissan's forecast or yours is more accurate.

The use of the phrase "significant numbers" in ChrisG's statement is something of an escape hatch, but it's also important--if Nissan (and every other company) release self-driving cars in 2020, they won't be a large fraction of the cars on the road for a long time after that. Cars on the road right now are 11.4 years old, on average. It will take a long time to for autonomous vehicles to cycle into the mix.

 

[dh87]

Alamout[/url]":1r5ie3qx]

You can focus on "test," and I can focus on "on public roads," and we'll revisit this is 2022 to see whether Nissan's forecast or yours is more accurate.

The use of the phrase "significant numbers" in ChrisG's statement is something of an escape hatch, but it's also important--if Nissan (and every other company) release self-driving cars in 2020, they won't be a large fraction of the cars on the road for a long time after that. Cars on the road right now are 11.4 years old, on average. It will take a long time to for autonomous vehicles to cycle into the mix.

My view is that if s-d cars meet 1/3 of realistic expectations of what they can do, everyone will rush to buy one. The replacement cycle won't really play into it, unless you're thinking about complete replacement of the cars.

 

[Alamout]

My view is that if s-d cars meet 1/3 of realistic expectations of what they can do, everyone will rush to buy one.

Most people can't buy a new car regardless of how nice it is. Cars are really expensive! That's why turnover is so slow--because lots of people buy used cars and keep them for as long as possible. It's not like 12-year-old cars are really nice, but they're all over the road anyway.

The replacement cycle won't really play into it, unless you're thinking about complete replacement of the cars.

What other replacement cycle is there? I'm not talking about new-car-buyers buying new cars every few years. I'm talking about how long it takes for a current-year model to get off the road, and it takes 15-20 years. As cars get even more reliable, the cycle can last even longer.

We were discussing how long it takes for a large number of cars on the road to be self-driving. Unless used cars don't count as cars, that means you have to consider the entire cycle.

 

[ChaoticUnreal]

Alamout[/url]":2f5il4jk]

My view is that if s-d cars meet 1/3 of realistic expectations of what they can do, everyone will rush to buy one.

Most people can't buy a new car regardless of how nice it is. Cars are really expensive! That's why turnover is so slow--because lots of people buy used cars and keep them for as long as possible. It's not like 12-year-old cars are really nice, but they're all over the road anyway.

The replacement cycle won't really play into it, unless you're thinking about complete replacement of the cars.

What other replacement cycle is there? I'm not talking about new-car-buyers buying new cars every few years. I'm talking about how long it takes for a current-year model to get off the road, and it takes 15-20 years. As cars get even more reliable, the cycle can last even longer.

We were discussing how long it takes for a large number of cars on the road to be self-driving. Unless used cars don't count as cars, that means you have to consider the entire cycle.

Depending on how well self driving cars due the cycle can be subverted by the .gov Just make some high % of freeways self drive only. Watch those self drive cars sell. Or depending on how complex the systems end up being could be done after market by certified techs. I wouldn't want some self driving car that joe schmo installed on the road but I could see retrofitting if done under the right conditions.

That said I don't really see retro fitting working due to the scale involved.

 

[Peldor]

There are ~250 million cars in the US fleet. New sales are around 15 million annually. It would be difficult to produce enough cars to replace 10% of the market.

Regardless of what the first self-driving car offers in terms of features, everyone will expect that the next version will be better. I can't foresee a mad rush of millions to purchase the first model(s).

Depending on how well self driving cars due the cycle can be subverted by the .gov Just make some high % of freeways self drive only

I take it back. It would be easy to produce 25 million cars in comparison to telling people 250 million cars are suddenly invalid for use on the transportation system their tax dollars have purchased. Laughably so.

 

[Frennzy]

Like it or don't like it, manufacturers (and others) see a potential market here, and are spending a lot of time, money, and brainpower to make it happen.

The major obstacles posited in this thread are simply those...obstacles...engineering challenges to be overcome. There is nothing impossible about the idea. It won't happen overnight, but few worthwhile things do. You can expect an iterative approach, with consumers and governments lagging behind achievements, but ultimately adopting them.

 

[Alamout]

Like it or don't like it, manufacturers (and others) see a potential market here, and are spending a lot of time, money, and brainpower to make it happen.

I don't know what this is in response to. I think everyone agrees that they're coming eventually. There are some much less supportable claims they're about to take over the whole market, which is just not possible.

 

[dh87]

Alamout[/url]":24k2u372]

My view is that if s-d cars meet 1/3 of realistic expectations of what they can do, everyone will rush to buy one.

Most people can't buy a new car regardless of how nice it is. Cars are really expensive! That's why turnover is so slow--because lots of people buy used cars and keep them for as long as possible. It's not like 12-year-old cars are really nice, but they're all over the road anyway.

There are a lot of people who drive older cars because a newer car is just a newer version of the same thing. A new car represents an evolution of the old car. I think that self-driving will be different; it's such a big deal that it will be worth replacing an otherwise serviceable car to get self-driving. It's true that some people can't afford to replace their older cars, and they'll be left out.

The replacement cycle won't really play into it, unless you're thinking about complete replacement of the cars.

What other replacement cycle is there? I'm not talking about new-car-buyers buying new cars every few years. I'm talking about how long it takes for a current-year model to get off the road, and it takes 15-20 years. As cars get even more reliable, the cycle can last even longer.

We were discussing how long it takes for a large number of cars on the road to be self-driving. Unless used cars don't count as cars, that means you have to consider the entire cycle.

The replacement cycle doesn't influence the first adopters. They can just buy a new car if the benefits are greater than the costs. That way, I expect that there will be a "significant number" of self-driviing cars in a hurry.

 

[Stainless]

Deus Casus[/url]":3dtv4dka]

Alamout[/url]":3dtv4dka]

My view is that if s-d cars meet 1/3 of realistic expectations of what they can do, everyone will rush to buy one.

Most people can't buy a new car regardless of how nice it is. Cars are really expensive! That's why turnover is so slow--because lots of people buy used cars and keep them for as long as possible. It's not like 12-year-old cars are really nice, but they're all over the road anyway.

The replacement cycle won't really play into it, unless you're thinking about complete replacement of the cars.

What other replacement cycle is there? I'm not talking about new-car-buyers buying new cars every few years. I'm talking about how long it takes for a current-year model to get off the road, and it takes 15-20 years. As cars get even more reliable, the cycle can last even longer.

We were discussing how long it takes for a large number of cars on the road to be self-driving. Unless used cars don't count as cars, that means you have to consider the entire cycle.

Depending on how well self driving cars due the cycle can be subverted by the .gov Just make some high % of freeways self drive only. Watch those self drive cars sell. Or depending on how complex the systems end up being could be done after market by certified techs. I wouldn't want some self driving car that joe schmo installed on the road but I could see retrofitting if done under the right conditions.

That said I don't really see retro fitting working due to the scale involved.

Retro fitting is not likely to happen in any real amount for the simple reason that sales would be poor (paying thousands of dollars to retrofit a car?), no major car make would pursue it as it's an obvious way to make new models stand out, and technical issues would be larger and more varied in a retrofit scenario.

New technology adoption simply takes a long time to spread through the working fleet of cars, ABS & Electronic Fuel Injection are both examples of relatively (compared to some like self drive systems of any level) cheap and very workable systems that took a long time to spread across the fleet, and EFI was pretty much mandated by emissions requirements.

Let's say Nissan brings a good system (hands off on freeways in summer say) to market in 6 years. It won't be across the line, probably would only be on the top models of say the Altima and up - right there you've cut sales figures to %25 at least. If all makers did it then you're looking at ~4 million cars per year. So 6 years gone and another 4 years for a model cycle before it trickles down another step - now we are 1 decade in with ~6% penetration under pretty favorable conditions. We haven't even considered the "unintended acceleration" sort of debacle that occurs in the USA yet.

The replacement cycle doesn't influence the first adopters. They can just buy a new car if the benefits are greater than the costs. That way, I expect that there will be a "significant number" of self-driviing cars in a hurry.

The problem is that "significant number" isn't a defined number. Somebody might call 30K cars significant, others would call that a pilot project.

 

[Alamout]

dh87[/url]":1bcj2r1o]There are a lot of people who drive older cars because a newer car is just a newer version of the same thing. A new car represents an evolution of the old car. I think that self-driving will be different; it's such a big deal that it will be worth replacing an otherwise serviceable car to get self-driving. It's true that some people can't afford to replace their older cars, and they'll be left out.

...

The replacement cycle doesn't influence the first adopters. They can just buy a new car if the benefits are greater than the costs. That way, I expect that there will be a "significant number" of self-driviing cars in a hurry.

Okay. I guess we'll just have to agree to disagree about fairly well-established consumer behaviors.

 

[dh87]

Alamout[/url]":2n8sqkcu]

dh87[/url]":2n8sqkcu]There are a lot of people who drive older cars because a newer car is just a newer version of the same thing. A new car represents an evolution of the old car. I think that self-driving will be different; it's such a big deal that it will be worth replacing an otherwise serviceable car to get self-driving. It's true that some people can't afford to replace their older cars, and they'll be left out.

...

The replacement cycle doesn't influence the first adopters. They can just buy a new car if the benefits are greater than the costs. That way, I expect that there will be a "significant number" of self-driviing cars in a hurry.

Okay. I guess we'll just have to agree to disagree about fairly well-established consumer behaviors.

OK. Just mark this page for study in 2022. I was going to end this with a sarcastic icon of some sort, but then I realized that I've been reading Ars for longer than the 8 years (±) between now and 2022, and you've been posting for 13 years. So, we'll check back.

 

[redleader]

Alamout[/url]":2j3b7pzq]

redleader[/url]":2j3b7pzq]I don't think you understood my post. I'm not saying infinite numbers of cars can occupy a volume. I'm just pointing out that the transport capacity per unit of area tends to be tremendously higher for roads than for trains because of the practical challenges of fitting a very large number of trains per area (extreme cost, difficulty of making overlapping subway tunnels, routing around building foundations, need for relatively large gaps between adjacent trains per tunnel, space used for stations, etc). For this reason, even in dense cities with extensive train systems, the road capacity of the city is generally far higher than the rail capacity.

I see what you're saying now, but I think you worded it poorly--roads never have a higher capacity per unit area of infrastructure. They might manage higher capacity over a general area given some cost constraints, but that's a different metric.

I'm not sure how I can make the statement "you can make cities a LOT more dense for a given cost (in both money and area)" more clear that density refers to money and area that I did in that post.

Alamout[/url]":2j3b7pzq]

I don't think anyone is saying that public transit is obsolete?

I don't know. In mass-transit threads there is often a post or two that brings up self-driving cars as if they obviate the need for investment in transit infrastructure.

stupid people believe stupid things. Lets let them be rather than bring them in.

Alamout[/url]":2j3b7pzq]
Shorter version: if you want a car-free or low-car-usage society,

Do I want that? Its not clear to me that I do. I want a more efficient city, and I'll take that either through better alternatives, better cars, or both. Whichever is more practical. This isn't something that seems worthy of ideology.

Alamout[/url]":2j3b7pzq]

Yes we do. While I understand that you like trains, they have extreme cost issues and more moderate issues with transit time and capacity. Furthermore, as a city becomes larger, these issues become more acute because of the difficulty of expanding capacity. If voters cared more about transmit, that would be great, but it won't bend a cost curve.

The cost issues are mostly a matter of sticker shock--infrastructure projects need to be evaluated on decade-long timeframes, and these projects look fine with that perspective*.

I'll read about this. Post the study.

Alamout[/url]":2j3b7pzq]
Expanding road capacity in a dense area is no picnic either.

I don't know, automated vehicles don't seem that hard to me as an engineer.

 

[redleader]

M. Jones[/url]":1f832kd6]

redleader[/url]":1f832kd6]
No, there are essentially no crosstalk issues with LIDAR. However, lets be clear, its not even certain that lidar will be the technology of choice. 60GHz microwave is probably cheaper and equally as good as optical because you can use electronic beamforming whereas lidar must be mechanically scanned or have multiple fixed emitters/detectors. If you want cars very close to each other, a single 360 degree phased array (or 2 180 arrays fore and aft) are much faster than a galvo scanned optical beam and certainly cheaper than many lidar beams.

Radar must normally be licensed, with the FCC. 60GHz is unlicensed, but mostly so because it's severely attenuated by resonance with atmospheric oxygen, and thus of severely limited range.

Not really. Its limited range compared to adjacent frequencies used for things like satellite communications, but the range of 60GHz radar systems is still measured in kilometers, which is realistically much further than you'd be able to image anyway given the existence of other cars (which strongly attenuate both radar and lidar in that they are opaque!)

M. Jones[/url]":1f832kd6]
Rain fade is a problem with all EHF spectrum, according to Wikipedia.

And its even worse for lidar given the even higher frequency!

 

[redleader]

Aatos[/url]":50g3sx1a]Wonder what the rain/snow limitations for microwave sensors are.

Rain/snow attenuate both optical and high frequency microwave beams through the same means, scattering. There are differences in how water absorbs microwave and optical frequencies, but they actually don't matter in this regime because the percentage of the air that is actually water during even a heavy rain storm is not that high. Thus absorption tends to be much less of a problem and can generally be neglected.

The types of scattering are actually somewhat different. Lidar is Mie scattered or even geometrically scattered because the rain drops are so large relative to the wavelength that they operate as miniature lenses/diffractive elements leading to forward peaked scattering. 60GHz is a 5 mm wavelength, which puts it in the rayleigh scattering range unless the rain droplets are very large. This will lead to more isotropic scattering.

In practice it doesn't really matter for coherent imaging systems like lidar/radar because they image based on time of flight. Any scattering, isotropic or forward peaked, will prevent accurate ranging if the scattering path length is much less than the imaging range. This is actually one of the advantages of time of flight based ranging as compared to other techniques.

 

[redleader]

dh87[/url]":87lxtjbe]

Alamout[/url]":87lxtjbe]

You can focus on "test," and I can focus on "on public roads," and we'll revisit this is 2022 to see whether Nissan's forecast or yours is more accurate.

The use of the phrase "significant numbers" in ChrisG's statement is something of an escape hatch, but it's also important--if Nissan (and every other company) release self-driving cars in 2020, they won't be a large fraction of the cars on the road for a long time after that. Cars on the road right now are 11.4 years old, on average. It will take a long time to for autonomous vehicles to cycle into the mix.

My view is that if s-d cars meet 1/3 of realistic expectations of what they can do, everyone will rush to buy one. The replacement cycle won't really play into it, unless you're thinking about complete replacement of the cars.

I think the replacement cycle matters a lot at the national level, and probably not very much at the individual city level. People in dense cities are much less likely to own a car in the first place in spite of much higher income on average. If automation leads to significant advantages, many of the buyers probably wouldn't be replacing, but rather buying a first vehicle. Thus, they would probably adopt a lot faster than national averages suggest.

If you're thinking about the highway system though its all about replacement. It'd take a long time before you got rid of all the old cars.

 

[Chuckstar]

Boneman[/url]":30imdc6k]
Have you never had a long highway commute? Are you just not getting it? How can you not see the utility of it? IT DOESN'T HAVE TO TAKE CARE OF EVERYTHING FOR YOU 100%. It just has to safely hand off control. "Alerting human to the issue and ensuring control is safely handed to human" is handling it. And they said they required the person to take control in those situations, but I don't recall it saying its because the system can't handle it. I'm sure they've got a lot of testing they want to do before they let loose their cars in high-risk situations like residential areas and on snow. Doesn't mean the car can't do it, it's just policy not to let it.

The article posted in the other thread said the guy's hands were on the wheel for only 14 minutes of his one hour commute. If I only had to be actively engaged for 25% of my two hour commute it would be a fucking godsend. Ok, sure I couldn't got into deep REM sleep in the current Google car iteration, but so long as the car is programmed to safely hand over control when it encounters a situation it can't handle, a little nap wouldn't hurt. hell even just being able to fart around on my phone would be pretty awesome. Which most people do on the road already.

I'm sure we're a long way from a car with a "layout in backseat and start counting sheep" mode, but for many people with a lot of highway driving on their commutes, the current version of Google Chauffeur would be simply amazing.

I have an hour-and-a-half each way mostly highway commute. No one, absolutely no one, wishes for a car that could take over the on-highway portion of the commute more than I do. I get it. But unless I can actually do something else (even if it's not napping), then it's a complete waste for me. I'm not interested in a situation where the car is driving but I still have to keep my eyes on the road looking for rare events.

And here's what you're ignoring: Right now these cars are only being driven by very responsible drivers who are (generally) staying alert to do things like watch for construction zones, take over in the rare emergency, and take over for the "hard" parts of the drive (i.e. surface streets, complicated interchange, not driving on snow, etc.) The question is, can you trust Joe Sixpack to be as responsible? If your answer is "no" (and mine certainly is), then they still need the car to be way smarter than it currently is before selling it to Joe Sixpack. Even Google admits as much. (It needs to be at least smart enough to know when it needs to stop and refuse to keep going unless the human takes over.)

And the way AI works, every bit smarter you need the machine to be is exponentially harder to implement than the last bit of smarts. (Maybe "exponentially" is not formally correct, but you get the point.) "Stay on this side of the yellow line" is way easier to implement than "read the orange construction signs and figure out where you're supposed to go". Hell, winding your way through a construction detour can be confusing even for humans, and it's not the kind of problem that computers do better than humans on. Even "if you see orange construction signs, make the human take over", is a difficult problem for computers, when you factor in the practical concept that it's useless if there's too many false positives.

 

[Chuckstar]

redleader[/url]":3g60k8s7]

Aatos[/url]":3g60k8s7]Wonder what the rain/snow limitations for microwave sensors are.

Rain/snow attenuate both optical and high frequency microwave beams through the same means, scattering. There are differences in how water absorbs microwave and optical frequencies, but they actually don't matter in this regime because the percentage of the air that is actually water during even a heavy rain storm is not that high. Thus absorption tends to be much less of a problem and can generally be neglected.

The types of scattering are actually somewhat different. Lidar is Mie scattered or even geometrically scattered because the rain drops are so large relative to the wavelength that they operate as miniature lenses/diffractive elements leading to forward peaked scattering. 60GHz is a 5 mm wavelength, which puts it in the rayleigh scattering range unless the rain droplets are very large. This will lead to more isotropic scattering.

In practice it doesn't really matter for coherent imaging systems like lidar/radar because they image based on time of flight. Any scattering, isotropic or forward peaked, will prevent accurate ranging if the scattering path length is much less than the imaging range. This is actually one of the advantages of time of flight based ranging as compared to other techniques.

Are there problems with the drops that hit the actual sensor? What I'm thinking of is that the raindrops on your glasses are much more of a problem for sight than the raindrops that simply fall between you and the object you're viewing. Of course, there are solutions for keep drops from forming on surfaces (wipers, RainX, etc.), but I'm as much curious as anything.

 

[HappyBunny]

Frennzy[/url]":195xs3f6]
The major obstacles posited in this thread are simply those...obstacles...engineering challenges to be overcome. There is nothing impossible about the idea. It won't happen overnight, but few worthwhile things do. You can expect an iterative approach, with consumers and governments lagging behind achievements, but ultimately adopting them.

While there are certainly big engineering challenges, I actually think the political side is the bigger obstacle. Self-driving cars are legal now in a few states, but only with someone still behind the wheel. And who knows what will happen once they start getting in accidents and causing injuries/deaths. They may well be much, much safer than human drivers, but that doesn't make the legal problems go away.

 

[dh87]

HappyBunny[/url]":2ix2rzzp]

Frennzy[/url]":2ix2rzzp]
The major obstacles posited in this thread are simply those...obstacles...engineering challenges to be overcome. There is nothing impossible about the idea. It won't happen overnight, but few worthwhile things do. You can expect an iterative approach, with consumers and governments lagging behind achievements, but ultimately adopting them.

While there are certainly big engineering challenges, I actually think the political side is the bigger obstacle. Self-driving cars are legal now in a few states, but only with someone still behind the wheel. And who knows what will happen once they start getting in accidents and causing injuries/deaths. They may well be much, much safer than human drivers, but that doesn't make the legal problems go away.

I'm not sure that I see this "legal problem" so clearly. At present, I carry insurance against accidents. If I were involved in an accident, it's very unlikely that I would be charged with a crime as long as I wasn't violating the law. Instead, my insurance company might have to make a payment if an accident were judged my fault. If s-d cars are safer, then my insurance premium is lower, and the insurance company pays in case of accidents. If my insurance company wants to sue the manufacturer because of a defect, they can. However, all the insurance company is really interested in is that the premiums cover the payouts. If an s-d car violates the law, then that's likely the fault of the manufacturer, unless I have specifically instructed the car to do something illegal.

 

[Peldor]

If an s-d car violates the law, then that's likely the fault of the manufacturer

Then you do see the problem very clearly. Currently the car manufactures have a very low chance of being found legally at fault in a car crash. It's almost always a driver error. When the car is the driver, now it's a design flaw.

 

[LordFrith]

Peldor[/url]":28f65c9h]

If an s-d car violates the law, then that's likely the fault of the manufacturer

Then you do see the problem very clearly. Currently the car manufactures have a very low chance of being found legally at fault in a car crash. It's almost always a driver error. When the car is the driver, now it's a design flaw.

But they seem to have been okay with adaptive cruise control, which easily could rear-end or kill someone pretty easily. My car, for example, allows cruise control down to stop-and-go traffic on city streets, meaning that someone could easily step in front of a seemingly stopped car, only to have it start up and hit them. So, manufacturers already cope with this potential liability.

 

[dh87]

Peldor[/url]":1ygqdbza]

If an s-d car violates the law, then that's likely the fault of the manufacturer

Then you do see the problem very clearly. Currently the car manufactures have a very low chance of being found legally at fault in a car crash. It's almost always a driver error. When the car is the driver, now it's a design flaw.

The companies will either carry insurance or self-insure. There seems very little chance that a company or an individual engineer could be found criminally liable. For insurance purposes, the only thing that matters is the statistics. I agree with some earlier posters who think that many individuals will not want to give up driving, ceding decisions to the car, even if it's statistically safer.

 

[NervousEnergy]

dh87[/url]":34jac9yf]The companies will either carry insurance or self-insure. There seems very little chance that a company or an individual engineer could be found criminally liable. For insurance purposes, the only thing that matters is the statistics. I agree with some earlier posters who think that many individuals will not want to give up driving, ceding decisions to the car, even if it's statistically safer.

I agree that will take quite a while and a lot of persuading and culture shift, since psychology trumps statistics. The statistical safety effect is an objective thing... over time, you can easily show that X number of folks using SD cars are alive today that wouldn't have been with human piloted vehicles, but that's an abstract. People have problems assigning weight to abstracts, and they sure don't have an emotional impact or make the evening news. That one in a million fluke technical problem, though, that drives a family of 4 off a bridge? EVERYONE is going to focus in on that, and damn the fact that for every 1 person a SD car kills it saves 1000.

I don't know we can fix that.

 

[Chuckstar]

LordFrith[/url]":3ig3zibp]

Peldor[/url]":3ig3zibp]

If an s-d car violates the law, then that's likely the fault of the manufacturer

Then you do see the problem very clearly. Currently the car manufactures have a very low chance of being found legally at fault in a car crash. It's almost always a driver error. When the car is the driver, now it's a design flaw.

But they seem to have been okay with adaptive cruise control, which easily could rear-end or kill someone pretty easily. My car, for example, allows cruise control down to stop-and-go traffic on city streets, meaning that someone could easily step in front of a seemingly stopped car, only to have it start up and hit them. So, manufacturers already cope with this potential liability.

No. Because with cruise control you are still in control of the car. Your hands are on the steering wheel and your foot is inches from the pedals and you're (supposed to be) paying just as much attention as if there was no cruise control. Not the case with a true self-driving car (at least not a self-driving car that's actually useful).

 

[LordFrith]

Why would my foot be inches from the pedal? I keep it flat on the floor as I lean back and let the cruise handle everything.

And what is the difference if the manufacturer simply says, "This is only an aid. You were expected to be in control."

 

[wco81]

If you get used to letting the car go auto pilot and your attention is elsewhere, it's doubtful that you can take over faster than the auto pilot can react.

 

[Chuckstar]

LordFrith[/url]":2nvek8uj]Why would my foot be inches from the pedal? I keep it flat on the floor as I lean back and let the cruise handle everything.

And what is the difference if the manufacturer simply says, "This is only an aid. You were expected to be in control."

Your floor is more than a few inches from the pedals? What kind of car do you have?