
The Highway Lane Next to Yours Isn’t Really Moving Any Faster - gkuan
http://www.citylab.com/commute/2015/05/the-highway-lane-next-to-yours-isnt-really-moving-any-faster/394079/
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gambiter
> And, for sure, sometimes the lane next to you is actually moving faster. But
> the point is that these cases are happening far less often than you think,
> and they largely fall outside our powers of detection.

Maybe I am falling into the illusion they speak of, but I am very suspicious
of their claims, especially because of the quoted point above.

I realize that anecdotes aren't data, but I makes me think of two things I've
noticed...

1) I have a family member with anxiety problems who has trouble just getting
into traffic. She hates changing lanes because she perceives it as extra
stressful, so she just stays put, content to follow the car ahead of her.
While she always eventually reaches her destination, there are times when I've
beaten her to a location by 10 minutes or more, all because I'm willing to
change lanes.

2) When I am in traffic, I look at the car ahead (of course) as well as the
farthest cars I'm able to see without obstruction. When I see the lane
'breaking up' several cars ahead and my own lane staying still, I tend to
change lanes to take advantage of the temporary speed advantage I'll have. I
can't count the times this has worked very well. The main reason is that
people tend to get lazy in bumper-to-bumper traffic, and when cars start
flowing there is inevitably one who is looking at his phone or just slow to
react. By timing it so that I can overtake these slow-goers, I tend to make
quite a bit of progress.

Maybe this study is focusing on people who only change lanes in response to
the movement in their immediate vicinity and not up ahead? Either way, it
seems like a shortsighted conclusion.

~~~
HelloMcFly
I think of it like this: traffic lanes are like slinkies side-by-side with
each other. Each slinky expands and contracts roughly equally, but not at the
same time. If you can hop from lane-to-lane such that you're maximizing your
time in the "expansion zone" before it contracts to a standstill then you'll
absolutely beat someone who never changes a lane.

More practically: don't change lanes from a "stuck" into a "moving" lane if
the moving lane has been moving at a steady rate for more than 30 seconds,
because it's probably about to contract and be stuck. If you're in a moving
lane, jump ship as soon as it seems like it's beginning to get stuck. This is
1/3 art, 1/3 science, 1/3 likely placebo.

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erikbern
I doubt this has much to do with traffic. It can be explained by another
observation: on average you spend more time in slow lanes.

The checkout at a supermarket has the same phenomenon. Let's say with 50%
probability you choose a line that takes 10 minutes and with 50% probability
you choose a line that takes 20 minutes. On average now 67% of the time the
other line will move faster.

~~~
yequalsx
I believe your analysis is incorrect. There is a 50% chance the other line
will move faster. With no additional new information, once you've chosen a
line to stand in, the probability you chose the slower line has not changed.

~~~
Retric
That's after 1 cycle. Assume you chose once per week for 10 years = 520 trips.
So, 50% of your _trips_ (260) you would pick the fast lane and 50% of the
_trips_ you would pick the slow lane (260). The sum of your slow trip _time_
is 20 * 260 = 5,200 minutes and your fast trip _time_ takes 10 * 260 = 2,600
minutes.

So, out of a total wait _time_ of 5200+2600= (7,800) minutes you spent 2/3 of
it in the slow lane and 1/3 of it in the fast lane.

~~~
Nadya
I think the last statement of the parent is causing the confusion.

>On average now 67% of the time the other line will move faster.

This should be: "On average, you spend 67%~ of your time in the slower lane."

On average the other lane is still only faster 50% of the time assuming the
odds are truly 50/50 - but you spend 67% more time in the slower lane.

~~~
JoeAltmaier
Gotta be careful with the word 'time'. 50% of your trips, the other lane is
faster. 67% of the time, its faster.

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Nadya
In California the lane to my left should be moving faster than the lane to my
right. Big rigs tend to stay in the right-side "slow" lanes and typically
aren't driving the 70-75mph everyone else is (although the speed limit is
supposed to be 65mph)

People in the far left lane or carpool lanes are sometimes going 80mph~

Small side note:

When I think highway, I think a 2 lane stretch of road without any stop signs
or traffic lights. The simulation makes it sound like they're talking about a
freeway.

~~~
QuercusMax
What's your definition of a freeway? I think this may be a regional
difference, perhaps - in Ohio, freeway and highway are generally synonyms, and
"freeway" may even be used for toll roads at times.

~~~
Nadya
This sums it up nicely.

[http://www.diffen.com/difference/Freeway_vs_Highway](http://www.diffen.com/difference/Freeway_vs_Highway)

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lifeisstillgood
It strikes me that this is a good explanation for "imposter syndrome". Let's
say you are a Dev Lead looking to understand your team relative to others and
you mentally measure "solid new features". Each team that releases a solid new
feature seems like a slip - and there will be a lot of those, but your release
(skip) will barely pass notice in your mind

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greggyb
Anecdata coming, so keep in mind that this is 100% scientifically verifiable
fact:

I find that this behavior is more typically the case when there is congestion
due to the number of lanes expectedly decreasing.

In the case where the number of lanes decreases unexpectedly (e.g. due to an
accident), the unobstructed lane seems to be slightly faster on average.

When the congestion is due to heavy merge/exit traffic, then I tend to find
the traffic moves more quickly as you move away from the merge/exit lane.

I always spot against other cars in my vicinity to see which lane is moving
more quickly.

I certainly do see the behavior illustrated in the article, but I don't know
that it's the dominant traffic behavior.

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codazoda
Although I didn't look really carefully, it looks like the data only took a
single lane change into account.

What about weaving into the lane that seems faster, passing several cars, then
switching back? It seems like the snaking effect would work to your advantage
if you always get in the lane where there is more distance between cars. Then
again, maybe it's perception.

~~~
knodi123
Imagine a theoretical highway where all of the cars except you are totally
stopped, and they are all very widely spaced. You could easily weave in and
out and make good time.

Clearly the ability to freely and easily change lanes is advantageous to a
single driver.

The problem is, in gridlock, this ability is pretty unlikely.

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joshdance
Unless they took a very large sample this might not be entirely true. Or put
differently the lane next to yours over a long time frame isn't moving faster,
but it does move faster at various points. By switching to the lane that is
moving faster at that moment, you can move faster than your original does over
the average.

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ikeboy
They give a reason why people might think they go faster, but don't prove that
they don't go faster.

See [http://www.anthropic-
principle.com/preprints/lane/cars.html](http://www.anthropic-
principle.com/preprints/lane/cars.html)

