
Is there any way I can alter my driving behaviour to help reduce traffic? - Tomte
https://www.reddit.com/r/AskEngineers/comments/4e80uu/traffic_engineers_is_there_any_way_i_can_alter_my/d1y78fb
======
maerF0x0
Do less of it? Probably the number one tip. But reduction is rarely an
acceptable solution.

~~~
wmeredith
This is the best answer. There was a billboard up in Kansas City for a while
that said, "You aren't sitting in traffic. You ARE traffic." I loved it.

------
cjak
You can improve the flow of congested traffic by keeping a gap in front and
encouraging other drivers to merge [1]. There are some intuitive diagrams and
animations in [2].

[1] [https://www.wsj.com/articles/one-driver-can-prevent-a-
traffi...](https://www.wsj.com/articles/one-driver-can-prevent-a-traffic-
jam-1476204858)

[2] [http://trafficwaves.org/](http://trafficwaves.org/)

------
johan_larson
Avoid rush hours as much as possible. If you must commute for work, work early
(7-3) or late (11-7) rather than normal business hours.

Of course, in some jobs this just isn't possible.

------
tutufan
Use all available lanes. If lanes are left empty ("for passing"), that
effectively reduces the capacity of the roadways, leading to traffic.

Let the downvotes commence...

~~~
_archon_
Note: I'm in the US, so my left lane is for passing, my right lane is for
cruising/exiting. If you drive in another country, your sides may vary.

If your recommendation is that everyone travel at the same rate in all lanes
of traffic, creating a rolling checkerboard pattern, I wish you luck. I
predict that we won't see this behavior until humans don't drive the cars
anymore. The closest thing in real life, with human drivers of all
temperaments and motivations, is a traffic jam. If even one person wants or
needs to travel more rapidly (or more slowly) than the mesh, the clash of
priorities, expectations, and behaviors can create a dangerous situation.

If we assume that human drivers are not uniform in needs, motivations, skills,
and equipment, then we can assume that their desired speeds may vary. In this
circumstance, we should arrange the rules of the road such that all drivers
are predictable and can navigate the roadway in a safe and efficient manner.
So far, this is done by telling slow traffic to stay right, unless they must
change left to pass someone slower* . Exits are typically on the right, so the
slow can always transact with exits without having to change lanes. If someone
fast wants to exit, they simply match speed with the right lane, change right,
and exit. Everyone is predictable, Everyone knows what to expect from everyone
else, and as such hazards are sparse. Imagine a sand dune on a treadmill in a
heavy wind. The bulk of the sand moves steadily along (bottom of dune = right
lane), but the grains that want to move faster due to wind (top of dune = left
lane) bypass the glut and blow over the top of it. This evens out the dune
into a flatter hill, then into a long, low rise. The dune treadmill can fit
into a smaller tunnel after a long time of faster grains passing the slower
grains. As grains pass, they recycle down to allow faster grains to pass. This
theory should allow for the most efficient flow of traffic in a multilane
system.

In such a system, if you have a car going slowly in the middle or left lane,
the system becomes less predictable. The faster cars have to slow to avoid
them, and may not be able to change left to pass due to faster cars. If
there's room, they can pass right, but that's not a common situation, it's not
what people expect, and it's therefore risky. This obstruction has the effect
of slowing down the entire system, creating a rolling road block, and
eventually a traffic jam as everyone following has to react to the obstruction
and find a way around it. Hazards are high in such a situation. Traffic can't
flow like water around the obstruction. One driver has made the roadway less
safe and efficient for all.

I'm not interested in downvoting you, this is good discussion. However,
although maximum throughput is theoretically achieved when all cars are
uniformly traveling at a high rate of speed in a mesh, there are several
factors that cause this to be an untenable ruleset right now. If someone on
the left has to exit, problems begin. If someone is in a hurry, or can't keep
up, or is limited in speed by equipment, law, or regulation, traffic begins.
If any traffic begins to take effect, it rapidly compounds into a slower mesh
in the best case, and a traffic jam in more realistic situations.

In all situations, the frequency of exits is inversely correlated to the
efficiency of transit.

*: Whether the right lane is entitled to change lanes left, or must wait for an oncoming faster car to go by, varies. In the US, if the car can get in the next lane safely, they're legal. In Germany, if they cause a car to have to slow down for them, they're illegal. I favor the German system, as it forces awareness and has less reactivity, which can be hazardous. My personal rule is to never merge, turn, or change lanes if someone else will have to react to me in any way. It is infuriating when someone turns from a secondary road with barely enough time to get their car into the lane before I would have hit them if I hadn't braked.

TL;DR your anticipation of the proposed policy being derided was correct, and
such derision is merited both from a safety and an efficiency standpoint. When
machines are handling transit, it may become a more feasible solution, but
that time is not now.

~~~
tutufan
Opinions differ, but I hope most will agree that the sooner human judgement is
removed from the roadways, the better. Self-driving vehicles are apparently
already safer than real-world human-driven vehicles, and there's little reason
to think that the latter will ever improve.

------
mmariani
Ride a bicycle or a motorcycle.

------
AznHisoka
1\. Not really for highway traffic but don't double park especially if there
is another car double parking nearby in the opposite lane. try and drive a
block ahead to see if theres any open space to squeeze into, and if not then
double park as a last resort.

2\. stop using your horn as a means of relieving frustration. horns should
rarely rarely be used as that 1 second to honk it could be used to REACT
instead.

------
nwah1
Great tips.

UPS implemented a system where they try to minimize the number of left turns,
which apparently had impressive savings in terms of fuel cost and time. I
wouldn't be surprised if left hand turns are also the most dangerous.

~~~
kwhitefoot
I think that safety was the reason they did it. I think that at least some of
their vehicles are right hand drive (to make getting out of the vehicle safer)
as well which means that left turns are noticeably more dangerous than right
turns.

------
drchiu
Particularly like and agree with letting people merge and avoid cutting off
people who want to merge. It's also good courtesy to behave this way.

------
jboles
After passing a slow car, pull in front of it (maintaining speed) so whoever
was behind you can also pass it.

------
euyyn
Interesting, counterintuitive at first, and well explained! Thanks for
sharing.

------
wcummings
You can not drive.

------
jmts
Congestion is a function of the capacity of a roadway, and the number of
vehicles trying to use it at a given point in time. I'd suspect that the only
thing any given citizen is able to do is reduce the number of vehicles at a
given time. This means either you don't drive (at that time), you car pool, or
you take public transport.

Assume all drivers like to maintain a gap of approximately 3 seconds between
them and the vehicle in front of them. That means that for a single lane,
there is a maximum rate of 1 car every 3 seconds at any given speed. If two
lanes at maximum capacity merge together, ideally they 'zipper' together but
there will no longer be a 3 second gap between cars, so everybody has to slow
down. Twice as many cars in the same amount of space suggests to me that
everybody now needs to go half as fast, and traffic backs up. The same applies
for multi-lane roads. A 4 lane highway has a capacity of 4 cars every 3
seconds, however the effects of mergers will diffuse across the lanes
somewhat.

Interestingly, we can treat slower vehicles in the same class as mergers, and
bottlenecks. Consider a gentleman in his vintage whatever going 60kph on a 3
lane, 100kph road. Aside from being dangerous, we can actually consider this
to be a moving merger from 3 lanes to 2. Now consider a leisurely cyclist at
35kph, or a broken down car in a side lane. The slower a road user is
travelling relative to traffic, the more they appear like a fixed merger. We
can also consider erratic movements by other drivers, which cause other road
users to slow down in a similar category.

Ideally, one should travel when roads aren't at capacity. That means that
users are have no longer hit their 3 second limit and have perhaps 5 second
spacing, or are even unable to see the car in front. This affords higher
speeds, more predictable behaviour, and a more peaceful commute for everybody.

If you can't avoid travelling when roads are at capacity, your only option is
to reduce the number of vehicles on the road. Car pool or take public
transport. If all users went from a single road user per vehicle, to four per
vehicle, demand would be reduced by 400%.

Interestingly, you might also consider riding a motorcycle. When cars are at a
standstill, motorcycles are able to filter through slow and stopped traffic.
Any given car replaced with a motorcycle will increase capacity slightly
depending on traffic circumstances. Obviously, one should evaluate their
interest and risks associated with such a decision before making the leap. A
confident driver making the transition to an unconfident motorcyclist may not
have a net positive outcome.

Unfortunately, due to the bottleneck case described above, I wouldn't
recommend cycling unless suitable bike trails are available or traffic speeds
are low enough.

~~~
eveningcoffee
> _Congestion is a function of the capacity of a roadway, and the number of
> vehicles trying to use it at a given point in time._

And driver behaviour. If drivers could rationally act for a collective good
then congestions could be avoided or limited, of course until certain
threshold.

Problem is that this kind of behaviour is not taught and is not enforced.

The best solution for congestion is limiting the need for driving through more
intelligent city planning (and through possibility to work from home).

------
fergazen
Yeah, when there is something interesting (like a wreck) on the side of the
road don't take your foot off the gas and slow down slightly to look. If each
person only slows down 1/100th of a MPH to look, then in a few minutes the
traffic will be at a stand still, just because everyone went just slightly
slower than the person in front of them to take a peek. No one seems to
understand this or want to change it and as a result we have massive slow-
downs in traffic just because of this stupidity. Just don't alter your speed.
Sure, take a peek when you go by, but please don't take your foot off the gas
you blithering idiots.

