Why a Traffic Flow Suddenly Turns into a Traffic Jam (2013) • Hacker News Board

Re: Why a Traffic Flow Suddenly Turns into a Traffic Jam (2013)

#41

Post by mattrp » Sun, Apr 28, 2019, 1:03 PM UTC

40four wrote: post #37

eljefe900 wrote: post #35

This article doesn’t mention a strategy you can take for breaking the wave: http://trafficwaves.org/ I originally found this info via the happy mutants at boingboing: https://boingboing.net/2013/06/23/howto-singlehandedly-erase... After using this technique for years, I can tell you that changing your mode of driving when you encounter traffic is difficult. Especially when you’re not used to “letting people pass”. Bu…

I liked the article, but I agree they should have made the way to correct this more clear. They briefly mention to increase you 'headway' in the end. I wish they would have hammered this point home, instead of waxing poetically about fluid-dynamical models, & detonation waves. The articles you linked do a great job at explaining how to fix this. Thanks for that! I believe this information should be taught as a basic…

My view of jams is they are caused by three expectations drivers have: 1) that the speed limit is still the “minimum speed” recommendation in heavy traffic. Ie, if it’s 65, one can still attempt to drive 74. 2) that the left lane is going to be the fastest in heavy traffic and 3) that somehow using the soon-to-be-closed lane in a lane closure/traffic shift scenario is “skipping the line.” In my view if we had adaptable speed limits /expectations of speed, we could probably avoid jams altogether if everyone agreed that 35mph was an optimal speed for heavy traffic. There would be far fewer brake lights and people would have far better reaction times (provided the slower speed didn’t give them false sense of security leading to checking their cell phones). In any case, try this the next time you’re in a jam- move to the right most lane. Not only is everyone around you doing the opposite (trying to go left for fast), but there are also people exiting the highway altogether... creating a slightly faster moving lane.

Re: Why a Traffic Flow Suddenly Turns into a Traffic Jam (2013)

#42

Post by drewg123 » Sun, Apr 28, 2019, 1:22 PM UTC

ikeyany wrote: post #19

robmaister wrote: post #16

Earlier quoted context omitted.

I've found that a lot of times it's not an onramp merging into you, it's people waiting until the last second to merge to an offramp and slamming on the brakes and/or cutting off someone to not miss the exit. I deal with this every day when I come home from work on my exit off the 405. People don't want to wait in line because it's slow, but it's slow because those people cut in at the last second and cause the entir…

You are absolutely correct. In my experience, traffic is caused by drivers who 1) refuse to plan ahead and 2) are fine with fucking over other people in an effort to mitigate that lack of planning ahead.

You're being generous by saying they "refuse to plan ahead". I think they are actively planning to "cheat" and cut in line, thus screwing over all traffic behind them.

I deal with a merge every day where 3 interstates come together. The first two (I64E, I195N) run together for 1/2 mile and finally merge from 2 lanes to one just before they merge into a dedicated lane on the destination interstate (I95N). They recently (last year or so) added the dedicated merge lane on I95N to try to speed things up, but it has not helped. The real problem is people waiting until the last second to merge 2:1 for the merge on to the destination highway.

I think things would be more effective if traffic from both interstates were forced to merge to a single lane as early as possible. Then traffic would be moving at close to the speed of the destination highway, rather than at 5mph due to all the lane jockeying resulting from the 2:1 merge just before the final merge onto I95N.

Re: Why a Traffic Flow Suddenly Turns into a Traffic Jam (2013)

#43

Post by jimktrains2 » Sun, Apr 28, 2019, 2:45 PM UTC

was8309 wrote: post #4

fosk wrote: post #2

In the US one of the biggest problems I have experienced is that drivers do not adhere to the international rule of having slow drivers on the right side of the freeway, especially in California. As a result to this there are more lane splitting episodes (even within the speed limit) in order to finally being able to keep moving at a faster speed because the lane is effectively blocked by other drivers. In addition t…

in Pittsburgh, part of the reason is that there are some exit ramps off the left lane. People who are afraid to change lanes get in the left lane and stay there for miles so they don't have to merge to get to the ramp

And we have weaves (2 roads merging and then splitting) that are much too short, and on ramps that have stop signs as you enter the highway. Sometimes the right becomes an exit only as well. Our roads are a mess, but I love them. Driving almost anywhere else feels easy.

Re: Why a Traffic Flow Suddenly Turns into a Traffic Jam (2013)

#44

Post by cryptonector » Sun, Apr 28, 2019, 10:46 PM UTC

Scea91 wrote: post #20

cryptonector wrote: post #11

Earlier quoted context omitted.

You don't get the "right" to "occupy" the left lane just because you're going fast. You have the obligation to yield the passing lane to anyone who wants to go faster. You do not know who has an emergency , and who doesn't. You don't get to enforce one law (speed limits) and flout the other (yield the passing lane). In fact, you don't get to enforce any laws if that isn't your job, and if it were your job, you should…

What is the rule exactly? 1) Yield the passing lane for anyone that wants to go faster or 2) Yield the passing lane if lane on the right is free. I am asking because I am not sure, but (2) would make more sense to me. You should not be required to break the speed limit to be allowed to pass the slower traffic.

The rule is mostly (varies by state) that if there are two lanes, or one lane and an improved shoulder (i.e., wide enough for a vehicle), then at your earliest convenience you must yield the left lane (or the only lane) to passers.

It's very, very simple.

BTW, in Texas it is now legal to pass on the right because of all those who fail to yield the passing lane. Passing on the right isn't very good, but it's what you get when people decide that the left lane is for themselves.

Re: Why a Traffic Flow Suddenly Turns into a Traffic Jam (2013)

#45

Post by cryptonector » Sun, Apr 28, 2019, 10:47 PM UTC

c22 wrote: post #32

Scea91 wrote: post #20

Earlier quoted context omitted.

What is the rule exactly? 1) Yield the passing lane for anyone that wants to go faster or 2) Yield the passing lane if lane on the right is free. I am asking because I am not sure, but (2) would make more sense to me. You should not be required to break the speed limit to be allowed to pass the slower traffic.

It seems to vary by state (see the link I posted in a sibling of your comment) but the general rule is that the left lane should only be used for passing in which case logically there should only be one "pass" happening at a time so yielding is not an issue.

Of course, in heavy traffic this goes out the window.

Re: Why a Traffic Flow Suddenly Turns into a Traffic Jam (2013)

#46

Post by cryptonector » Sun, Apr 28, 2019, 10:48 PM UTC

sl1ck731 wrote: post #21

cryptonector wrote: post #11

Earlier quoted context omitted.

You don't get the "right" to "occupy" the left lane just because you're going fast. You have the obligation to yield the passing lane to anyone who wants to go faster. You do not know who has an emergency , and who doesn't. You don't get to enforce one law (speed limits) and flout the other (yield the passing lane). In fact, you don't get to enforce any laws if that isn't your job, and if it were your job, you should…

You don't get the right to speed due to an emergency. Call an ambulance. To your other point, it is not "flouting the other" law (yield the passing lane) if its 1 person doing 100 mph trying to pass you. The law is in respect to the "normal" flow of traffic, not the fact that any one person is trying to go faster than you.

I don't care what you think of whoever is trying to pas you, so long as you let them pass. That's the law. Let law enforcement worry about who is violating it; you follow the law.

Re: Why a Traffic Flow Suddenly Turns into a Traffic Jam (2013)

#47

Post by apple4ever » Mon, Apr 29, 2019, 5:11 PM UTC

fosk wrote: post #2

In the US one of the biggest problems I have experienced is that drivers do not adhere to the international rule of having slow drivers on the right side of the freeway, especially in California. As a result to this there are more lane splitting episodes (even within the speed limit) in order to finally being able to keep moving at a faster speed because the lane is effectively blocked by other drivers. In addition t…

I believe its because of what some of the above commenters discussed: that some drivers believe not only do they have a "right" to the lane, but its their job to enforce the speed limit.