
To reduce traffic, ditch yellow lights and form platoons of self-driving cars - bpierre
http://arstechnica.com/cars/2016/03/to-reduce-traffic-ditch-yellow-lights-and-form-platoons-of-self-driving-cars/
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peatmoss
I read the original article discussed by Ars here this morning, and the
authors note that they didn't consider the scenario in which multiple
intersections exist in a connected roadway network. Also missing was any
discussion of pedestrians, bicycles, or non-self-driving cars. This is
interesting work, and may have applications in some limited settings, but I
wouldn't bank on seeing it too soon even after self-driving vehicles are
commonplace.

Also, as a planner, I feel obliged to point out that the title "To reduce
traffic" can never be true. In a best case scenario this would allow more
vehicles to use the same amount of roadway resource--i.e. increase traffic. As
for congestion, that's widely accepted to be an equilibrium state. So if these
intersections were successful at improving roadway efficiency, we'd expect to
see the additional capacity eaten up by increased demand.

~~~
ccvannorman
I used to study traffic a lot, and it's definitely true that eating additional
capacity leads to more gridlock assuming the same type of driver.

However, consider the freeway case as a starting point. Freeways lock up
because of congestion resulting from too many people merging on, causing
people to plan poorly/brake suddenly, which leads to a recursive accordion
effect, which leads to 5-10 mph stop and go for hours.

However, the actual __throughput __of cars past any one point on the freeway
is actually __higher __at around 40-50 mph (you should get 1.5 - 2x throughput
that you get at 10mph), assuming everyone is organized enough[1].

Now imagine pace cars whose sole job it is is to buffer and reduce the
negative impacts of poor human decision on the freeway, with a total car
increase of only 1-5%.

[1] Sorry, I don't remember the source, but I swear I had one a few years ago
when I was heavy into traffic.

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dwyerm
I haven't seen the specific study you mentioned, but it is referred to in the
book, "Traffic: Why We Drive the Way We Do (and What It Says About Us)" by Tom
Vanderbilt. If you are at all interested in traffic, this is a very good book
to start with.

Mind you, despite being very convincing, I'm not yet a late-merger. I do find
myself trying to drive more smoothly, though.

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nenreme
Lol, US is so slow, used in Ethiopia for ages
[https://www.youtube.com/watch?v=oKGeuAoGW_E](https://www.youtube.com/watch?v=oKGeuAoGW_E)

~~~
ethagknight
Panic inducing to anyone unfamiliar! On Monday there were some HN posts about
people having peaceful, serene SlowTV video streams in the background while
they work. A SlowTV channel of this would be the opposite!

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Nr7
I'm sure it would work for just cars, but what about pedestrian crossings?

~~~
giancarlostoro
Disney Springs (in Orlando, FL - Note: used to be called "Downtown Disney")
got rid of crossings and made tunnels / bridges instead to keep traffic
flowing. Probably not as ideal outside of Disney though. They're expanding /
rebuilding the whole area. I no longer drive through there worrying about
pedestrians altogether.

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trejitus
Or just put in roundabouts instead of lights.

[http://safety.fhwa.dot.gov/intersection/innovative/roundabou...](http://safety.fhwa.dot.gov/intersection/innovative/roundabouts/)

~~~
peatmoss
Which, in a single lane scenario, have the additional benefit of decreasing
collisions and injuries for pretty much all involved. They are also
successfully proven in a roadway network (the proposed scheme here doesn't
consider that case). Roundabouts are a great analog tech.

Roundabouts get less compelling when they are multi-lane (can start to suck
for pedestrians and bikes in particular). They can also take up lots of space.
But, on the whole, roundabouts be good.

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bliti
This blog post is based on a paper[1] that explores using "slots" to arrange
traffic and move the vehicles smoothly like a system of cogs. It brings up the
fact that our current transportation infrastructure needs to be updated for
true autonomous driving.

[1]
[http://journals.plos.org/plosone/article?id=10.1371/journal....](http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0149607#abstract0)

