
Study: Intelligent Cars Could Boost Highway Capacity by 273% - eguizzo
http://spectrum.ieee.org/automaton/robotics/artificial-intelligence/intelligent-cars-could-boost-highway-capacity-by-273#.UEZAIqv-vCA.hackernews
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paulsutter
The introduction of radial tires caused a collapse of the tire industry.
People didn't start driving four times as far when the useful distance of a
tire increased.

Human driven cars are idle 95% of the time. Many fewer self-driving cars could
handle the same capacity with ride sharing services like uber.

I'm concerned that auto manufacturers would take actions to prevent this
outcome, reducing the potential.

EDIT: silverstorm that's an awesome point

~~~
vijayr
If software drove all cars, driving cars would become much more efficient

1\. cars will last longer, which would make car manufacturers unhappy

2\. cars will become more fuel efficient, which would make fuel industry
unhappy

3\. insurance rates will go down, which would make insurance industry unhappy

4\. number of accidents would be less, cars would require lesser maintenance
which would make mechanics unhappy

etc

But, more people (elderly, people with disabilities) would buy cars, so number
of cars sold would go up. Also, it would open up whole lot of possibilities on
the software side, construction industry etc (what if roads are designed for
super efficient drivers, than humans?).

Overall, it would be awesome to watch this happen - kudos to Google for
tackling this.

~~~
eumenides1
5\. Housing prices would go down in major cities in the short term? Less
demand to be in a metro area?

Living in the suburbs would be much more palatable because you could convert
your "drive time" to "internet/reading time".

Auto driving cars would be not be just a disruption (i hate that word) to the
auto industry, it would be an earthquake that would have many aftershocks to
the economy as a whole.

~~~
rogerbinns
> ... because you could convert your "drive time" to "internet/reading time".

Sadly some of us humans are now genetically dead ends. I'm one of those people
who gets car sick unless I'm looking out the window, best in the front seat
and with cool air blowing. Consequently I can't really read or Internet. (If I
look at a paper map for about 60 seconds I'll be on the verge of puking.) So
even if I wasn't driving I can't really use the time for anything else (can't
sleep either).

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wtvanhest
3 points should be considered:

1) Even with robots there will be unknowns which the robots will have to deal
with which will still require a margin of safety. Likely that margin of safety
will be lower with robots, but definitely will not approach 100% capacity.
(things like tire blow-outs, deer, even sudden rain etc).

2) Road wear will still need to be considered in any cost benefit analysis.
Presumably road wear is less of a factor than jamming cars on the road, but I
don't know that for sure and someone should do the math on that. There is also
a point where if you exceed a certain capacity percentage, anytime road work
needs to be done it would dramatically impact traffic since there is less of
buffer to absorb the lack of lanes.

3) As we increase capacity, we may run in to additional problems that we
cannot imagine. Bridges for example could be an issue as the amount of weight
would be increased dramatically, even more remote a possibility would be
damage from additional vibrations etc. Those are just ideas that come to mind,
but there are probably many other risks we are not considering.

Overall, I am 100% for robotic cars, robotic passenger jets, etc. I just
wanted to brainstorm a few future problems that may need to be considered as
we move forward. The last thing I want to see is a 5 year setback.

Then again, the engineers at google and elsewhere have probably considered all
these things which just seem new to me as a casual outside observer.

~~~
ajross
I think your broad point is correct; no system can be perfect. But most of
your criticisms have straightforward rebuttals. Robots, being robots, are
going to be _inherently safer_ at the stuff you mention (tire failure, sudden
obstacles, weather) simply because those things are "dangerous" _precisely
because_ they are unforseen and require the driver to take action quickly.
Robots are faster.

Road wear is a cost, but it scales at worst linearly with traffic. I can't
imagine anyone crying because we can now build ($$$$) half as many lanes of
highways but much repave ($) them twice as often.

And the bridges things is just wrong. Bridges are obviuosly designed for
maximal loads, which in this case would be a bumper-to-bumper traffic jam of
even more weight than a packed stream of robots. And that happens routinely.

~~~
001sky
We don't want to mis-underestimate the complexity driving a car. The dynamics
of obstacle avoidance, for example. Have you ever been hit by a deer?. Had a
blowout (not a flat) on an SUV, say in a decreasing radius, off camber turn?
Can you solve for some of these considerations? certainly. But you would need
extra-ordinary technology. The dataset for camber-level 3D GPS maps, for
example = large. What about a sinkhole or collapse of roadway al-la
Embarcadero freeway? Or the Collapse of the Bay Bridge? What about hydro-
planing after a rainstorm in CA? Lastly, ABS can be dangerous on snow, dirt
and other imperfect road surfaces. How do you feather the brakes? Just some
edge cases. On the cost side, the interstate system is ~complete. So, you wont
be saving money by avoiding future construction, in proportion. You will just
be speeding up the depreciation of the existing capital infrastructure. So,
again, that's not a clear cut case there.

~~~
ajross
I'm not following those edge cases at all. Those all sound pretty fatal to
humans too, or invoke driver skills ("feather the brakes", seriously?) that
real-world drivers don't have. The point here isn't to be perfect, it's to be
_better_. And that is, frankly, a very low bar.

Also: I'm very amused by your assertion that the interstate highway system
(probably 10% of which is under expansion at any given time in any give metro
area, and the remainder of which is rapidly approaching capacity and/or
experiencing routine unplanned congestion) is "done".

~~~
001sky
_I'm not following those edge cases at all_

Understood. So I will explain a bit more in depth. But, the things I laid out
are pretty basic. The dynamic responses of a vehicle under motion works
something like this.

(1) Balance. The car is never level. As you accelerate, there is inertia. The
drive train and the chassis do not move in unison. They are connected by
"Springs". This is like an airplane: attitude. So, the forces on the car and
the road are different, but related. And there is a lag.

(2) Dynamics. Accelerate, nose up + ass down. Decelerate, nose down+ass up.
The road is not straight? Similar for a turn (tilt left, tilt right). Now,
combine. What happens? There is a dynamic weighting applied to all 4 corners.
Go into a rt turn? Weight front left. Unweight rear right. etc. So, the point
is that the friction is changing in each corner as you drive. The friction
must exceed the energy of the car, or you will slide like on ice, etc. But,
for the reason you brake in a turn, this is not always guaranteed, etc.

(3) Topology. Now, add some complexity: The road is not flat. This changes the
calculation of the weighting for each tire. A tire on a 45degree incline is
not holding as much friction as on a 2 degree one. This is like standing on a
sand-slope, etc. Just basic idea. Now, The traction is a function of the
weighting of each tire, _plus_ the relative position of the tire to the road
surface.

(4) Environment. Also, you have to consider a few other things: Do you know
the co-efficient of friction of the road surface? Clean? Dry? Wet? WIth autumn
leaves? What tyres do you have? What is the friction curve with relation to
the rubber type and the ambient air-temperature? Oh, and by the way where is
the tread depth? Today? Yesterday? These are all things that go through the
mind of a trained driver and are not un-common knowledge (think: f1, rally).
Same thing with left-foot braking, not using ABS, non-abs brakes on
snow/ice/dirt/ etc.

(5) Complex System. If you cannot predict any part of this, you run the risk
that the inertia of the car from speed etc >friction => loss of traction,
accident, crash etc. This means: If you don't know the "camber" of the turn,
your math is a problem. You might know that you are turning right at x
degrees, but what will the turn be in 100m? constant radius? or not? What if
you change lanes in the turn? etc. Now, you can topo-map solve this at high
enough resolution. Eg., something akin to a race-track, in a video game. Go to
Laguna seca, and put that in a computer. Problem here, though, is scale: like
1 inch topo variances or something, but that data set for CA state? Is huge.
You don't have it. How would you even get it? What is your other option?
Terrain acquiring radar? That might work. There is probably something in 60ghz
and up that in theory might work. But you are line of sight constrained and
now how far out can you look? 10m? What is the system's reaction time? How
fast are you?

(6) Road hazards. Similar problem here. If there are abrupt changes. How do
you acquire them? A sinkhole. A pot-hole (might break your wheel, etc) These
are things not on a map-set. A live person just drives around them. But, what
about a freeway? 6 Lanes, everyone is packed in like sardines. Does the guy in
lane 6 know the guy in lane 2 is going to swerve? If he doesn't swerve (an
breaks his wheel) what happens? The bridge failures are an example similar. If
you are driving, you just look and see: no road. But, what if you are on auto-
pilot? Who tells the computer there is no road? Same thing flash flood. Even
worse, is hydroplaning risk (like 1/4 inch of standing water, say). If you are
not driving are you paying attention? If you don't feel the steering wheel,
how do you know? Can you put that into the computer?

That being said, they are doing amazing things with traction control systems
on motorcycles right now. So some of this may get figured out. But you will
not see a guy with all of this tech riding no hands/no brakes, etc. This is
strictly in addition to user input and continual monitoring of the controls.

____________________________

The Interstate System

Do you have experience actually navigating? Like, say long stretches accross
the USA? At continental scale? The Interstate systems is what it is. Its "90%"
done. There is not 1000 mile segments being built. Max is 100 miles, and even
that is incredibly difficult (permits, etc). Also, those are not "capacity"
related build outs, you are talking only a couple of missing geographic links.
New lanes/etc are a different animal (thats maintenance, for the most-part).
Put another way, US is not going to rip out 2/3 of the roads and put 3x the
traffic on the smaller footprint, to get to a break-even case. Now, you want
to increase by 278% more cars/hours on the system? OK fine, but it will cost
you. Its basic math, no? Also, the economics of construction don't work out
that you save money by only "fixing" half the lanes or whatever. Lastly,
consider the purpose: more capacity? History shows, no matter how many lanes
you put down, the 405 fwy will be in Jam at 4-6pm in LA. Its not just
rubbernecking. It is a larger social issue: people will procrastinate. Now
they are in a "hurry". Oops. [As the saying goes, sometimes there is no
engineering around stupid =D.]

Other Safety cases.

The point of these cases is not that they are per-se fatal. It is that they
require real-time rapid-terrain-acquisition to avoid making the problem worse.
Deer is similar. I doubt a basic Lidar is going to acquire a deer in the brush
that jumps out in the road. It might, with thermal imaging, make it possible
to _see_ hiding off to the side. But, the calculation would need to be
predictive in a what which is pretty amazing.

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btilly
I'm curious what happens when you have highways filled to capacity, and then
more cars are added.

A busy highway moving smoothly at capacity is like a super-cooled fluid. As
long as nothing goes wrong, it can last, but the second you introduce some
delay, somewhere, you wind up with a rapidly expanding solid (ie traffic jam).
Intelligent cars boost the capacity of smooth traffic more than they do the
capacity of bumper to bumper slow traffic, and hence the transitions from
"awesome" to "oh shit" should be much nastier than they are now.

The traffic jams of the future could make our current ones look tame.

~~~
paulovsk
please, could you elaborate on this? I loved the metaphor.

>"As long as nothing goes wrong, it can last, but the second you introduce
some delay, somewhere, you wind up with a rapidly expanding solid "

~~~
btilly
The capacity of the road as being the number of cars passing by per second.
Which is the number of lines times the rate at which cars are traveling,
divided by the distance between cars in a lane. Now compare:

Smooth: Going 60 mph and leaving 2 car lengths of space, so the distance from
front bumper to front bumper is 3 car lengths.

Congested: Going 30 mph and leaving 1 car length of space, so the distance
from front bumper to front bumper is 2 car lengths.

In the former road you go 2x as fast and need only 1.5x as much space, so the
former road has a third as much capacity as the latter. So if cars are moving
along a highway already operating at capacity into a congested area, cars are
arriving at the transition faster than they are leaving. Thanks to the law of
conservation of cars, excess cars must accumulate at that transition, and
since they have nowhere to go, they wind up parked in a traffic jam. And as
long as the road feeding it is at capacity, that traffic jam grows.

From the point of view of the driver, this is what it looks like. You're
sailing along in smooth fast traffic, and then hit a sudden traffic jam with
no warning. After sitting there for a long time the road starts moving again,
but goes much slower.

This is common experience in Los Angeles traffic. And a significant fraction
of accidents happen at that sudden transition from smooth sailing at 60 mph to
a dead stop. (In fact my wife got rear-ended in that exact scenario a year and
a half ago on the 405 near Los Angeles airport.)

~~~
paulovsk
Thanks! Really really insightful.

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a-priori
Wow, about a month ago on Reddit, I made a quick calculation where I predicted
a 250% improvement in capacity.

[http://www.reddit.com/r/Futurology/comments/y28g8/suspend_al...](http://www.reddit.com/r/Futurology/comments/y28g8/suspend_all_pessimism_for_a_moment_share_a_short/c5s0xqs)

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yanowitz
Is it just coincidence that this is essentially e? I know the natural log pops
up in all kinds of unexpected places. Is this one of them?

~~~
SilasX
I'd be more concerned about the phony precision. Not 250%, not 270%, no --
273%.

~~~
saraid216
Considering this references an actual research paper, I'd wait to actually
_read_ the paper before calling the precision phony.

~~~
SilasX
No, you don't need to read the paper to conclude that three significant
figures of precision is warranted.

Perhaps the research is good, and this is just a case of PR having unwarranted
input into the labeling, but that still wouldn't justify the headline.

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bencpeters
I've always had a few questions about the move toward fully automated cars
(and I don't mean to raise these as luddite objections, I'm just curious how
it will play out, and what steps are being taken to address this)

1)How will manual cars (and motorcycles) be managed once we have non trivial
percentages of cars on the road automated? Will there be automated-only
highways? Automated-only lanes? Is the beginning of the end for those of us
who really enjoy driving (or motorcyles?). Or will those things just be
limited to non-urban/track environments?

2)How does all this automation & closer car traveling @ high speeds work when
natural events intercede. The most obvious one is weather (rain or snow),
which can be a huge problem for cities as is, but it seems like having cars on
the road with no "bubbles" of space to buffer great exacerbates the potential
for massive accidents when there is marginal traction. Secondly, in many areas
of the country, wildlife on highways is a very common occurrence (even in
cities there's the occasional road debris/unexpected obstacle). I wonder how
well an at-capacity automated highway could react to a sudden bit of road
obstruction w/o running into a massive accident (or massive traffic jam)
situation.

Of course, many/most human drivers don't handle adverse weather or unexpected
obstacles very well either, so maybe these are just facts of driving, not
arguments against automated cars as such. Still, I'm interested to see what
attempts are being made to mitigate the effects of such variables.

~~~
maxerickson
I think there are a lot of situations where automatic cars would leave more
space than humans, who seem to be prone to (unnecessary) tailgating.

~~~
error54
Let's not forget traffic jams caused by rubbernecking.

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moskie
This type of information has made me rethink my overly-negative opinion of how
the United States has chosen to spend its transportation infrastructure
efforts. I've always been under the impression that car-centric designs are
grossly inefficient, and used primarily due to culture and profit of the
automobile and oil industries, while putting actually transportation
efficiency on the back burner.

But automated cars could flip the efficiency numbers around. Really excited to
see where this technology takes us.

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praptak
This is not necessarily good news. Among other thing this means the capacity
for pollution also rises, although hopefully not by the same factor - maybe
automated cars can be more energy efficient than human drivers.

~~~
dwiel
There is a large amount of pollution cause by the manufacturing of cars, which
can have a net benefit. Another benefit is that you could use very efficient
cars for the trips that they are suited for like going shopping for groceries
by yourself, and inefficient ones like picking up a new refrigerator.

That said I'm also worried that it could increase the time spent in cars since
there won't be as much negative feedback from stressful/boring/unproductive
driving.

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tonylemesmer
Am I missing something here? Already our motorways / highways are not being
used at this higher capacity but when something bad happens there is no
redundancy. Everything grinds to a halt. What's the desire to make this worse?
Also does it not put even more pressure on the roads leading to the highway? -
increasing congestion to the point where having higher usage of highways is
pointless.

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michaelpinto
I think self driven cars are going to be an amazing blessing to senior
citizens — this could really reinvent suburbia in a good way.

~~~
ncavig
True, but not even that limited. Any individual that could benefit from not
having to concern themselves with the outside environment. In addition to the
senior citizens, you also have the handicapped, the makeup applicators, the
cell phone users, limited eyesight drivers, the overall bad drivers, and more
importantly, impaired drivers (alcohol especially).

Not just performance in terms of efficient driving and merging, but also
safety and essentially taking human operator error out of the equation (for
the most part)

~~~
sp332
_Any individual that could benefit from not having to concern themselves with
the outside environment._

I think people will take this way too far. They'll turn on the autopilot and
take a nap while blasting through a school zone or something.

~~~
Goronmon
_I think people will take this way too far. They'll turn on the autopilot and
take a nap while blasting through a school zone or something._

If the car can't handle those situations, then it's not going to be a very
useful intelligent car.

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001sky
Isn't the historical _problem_ 100% of feasible capacity will be used?

~~~
SilasX
Bingo. Until you can handle the problem of people moving further out to make
up for the shorter commute, you're just deferring the problem, not fixing it.

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dvanduzer
Come on guys, you're the IEEE. Lead the story with the second set of graphs,
not the first set of graphs.

I'm also going to go out on a limb and guess that this study doesn't account
for the inevitable malware when the majority of vehicles are communicating
with each other.

~~~
EliRivers
"I'm also going to go out on a limb and guess that this study doesn't account
for the inevitable malware when the majority of vehicles are communicating
with each other."

It's not inevitable. The simple solution to malware - just don't run any
software you didn't have when you were first turned on - seems pretty solid
here. Software updates handled the way airliners do it - not by letting the
consumer reach out into the aether and grabbing whatever shiny malware
infested dreck he can find.

~~~
dvanduzer
Aha. s/malware/bad actors/

A little late getting back to the party, but the problem I intended to
highlight was the potential for DDOSing the traffic network, or someone
otherwise gaming the system.

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elchief
With the right software, they will be able to drive like a school of fish, at
very high speeds.

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TechNewb
Intelligent societies could build infrastructures and communities that don't
need cars.

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samstave
I sure hope Google and Tesla are partnering to bring the tesla's next model to
the market as the first fully electric and robotic self driving car.

~~~
JoeAltmaier
Tesla's goal is to create a fun-to-drive electric car. It would be opposite to
their goal to create a self-driving car.

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brittohalloran
My first thought is minority report "pods"

