Dock/Undock to reset 30 minute timer

[dasgeh]

@KLizotte 58981 wrote:

The bike shoalers defense.

That’s like saying taking free condoms is theft. One is safe, legal and better for all. The other is the opposite.

[Tim Kelley]

I’ve got to say, I like the way this thread has gone. Lots of interesting points back and forth!

[mstone]

@dasgeh 58990 wrote:

That’s like saying taking free condoms is theft. One is safe, legal and better for all. The other is the opposite.

Yeah, and since there’s no limit by policy, there’s no ethical issue in just taking the whole bin every time you go by and keeping them in your room in case you need them, right?

[KLizotte]

@dasgeh 58990 wrote:

That’s like saying taking free condoms is theft. One is safe, legal and better for all. The other is the opposite.

WTF?! That makes no sense at all. Taking free condoms isn’t theft in the most technical sense of the term because you haven’t taken anything away from anyone else (what economists call rival, excludable goods) even though they may have positive externalities. Cutting in line, on the other hands, means that you have taken time (and space) from someone else. Non-toll highways are what economists call a non-excludable good that may or may not be rival depending on the congestion level. You seem to be mixing up the concepts of rivalry, excludability and externalities.

A bike shoaler will argue that there is asphalt at the start of the line that he or she can squeeze into ahead of everyone else therefore it is ok. Same as a car trying to squeeze into the front of the line by riding ahead in the disappearing lane. Maybe the drivers aren’t being the most efficient users of the roadway but there is a reason why most people patiently waiting in line won’t give way for a shoaling driver in most instances (fairness trumping efficiency).

[dasgeh]

@KLizotte 59001 wrote:

WTF?! That makes no sense at all. Taking free condoms isn’t theft in the most technical sense of the term because you haven’t taken anything away from anyone else (what economists call rival, excludable goods) even though they may have positive externalities. Cutting in line, on the other hands, means that you have taken time (and space) from someone else. Non-toll highways are what economists call a non-excludable good that may or may not be rival depending on the congestion level. You seem to be mixing up the concepts of rivalry, excludability and externalities.

A bike shoaler will argue that there is asphalt at the start of the line that he or she can squeeze into ahead of everyone else therefore it is ok. Same as a car trying to squeeze into the front of the line by riding ahead in the disappearing lane. Maybe the drivers aren’t being the most efficient users of the roadway but there is a reason why most people patiently waiting in line won’t give way for a shoaling driver in most instances (fairness trumping efficiency).

So all highways should be one-lane? Because that’s the logical end to “merge as soon as you see the sign”.

In Germany, where they have good driver’s ed, they teach people that the most efficient and fair way to deal with the disappearing lane when there’s traffic is to stay in your lane (disappearing or not) until the merge point, then zipper merge. Maximize use of the asphalt (when there’s not traffic, it’s safer to get over early, and maximizing asphalt use isn’t a concern). And that’s what most people do. Both lanes end up with the same average speed.

Here, people move out of the disappearing lane much earlier, then think that those people continuing on in the lane are somehow attacking them? If I’m in the disappearing lane, 2 miles from a merge point, and everyone else merges, am I supposed to merge, too, slowing all the people in the non-disappearing lane behind me? Or continue on at a safe speed until the merge point?

[KLizotte]

@dasgeh 59012 wrote:

So all highways should be one-lane? Because that’s the logical end to “merge as soon as you see the sign”.

In Germany, where they have good driver’s ed, they teach people that the most efficient and fair way to deal with the disappearing lane when there’s traffic is to stay in your lane (disappearing or not) until the merge point, then zipper merge. Maximize use of the asphalt (when there’s not traffic, it’s safer to get over early, and maximizing asphalt use isn’t a concern). And that’s what most people do. Both lanes end up with the same average speed.

Here, people move out of the disappearing lane much earlier, then think that those people continuing on in the lane are somehow attacking them? If I’m in the disappearing lane, 2 miles from a merge point, and everyone else merges, am I supposed to merge, too, slowing all the people in the non-disappearing lane behind me? Or continue on at a safe speed until the merge point?

I’ve always found that both lanes stay full until the merge point; what ticks people off is when shoalers use the break down lane or an exit lane then try to squeeze in. But very generally speaking, I think most folks would still think you are trying to cut in even if the merge lane wasn’t being fully utilized because people tend to prioritize fairness over efficiency. For instance, I can get through the checkout line far faster than anyone with kiddies with them (or shopping carts filled with family sized amounts of stuff), does that give me the right to jump ahead of them? How about if all singletons jump to the front of the line at all times? As much as that might benefit me, I’m not advocating it (though I do wish the Mall’s museums would offer adult-only hours).

[dasgeh]

@KLizotte 59016 wrote:

I’ve always found that both lanes stay full until the merge point; what ticks people off is when shoalers use the break down lane or an exit lane then try to squeeze in. But very generally speaking, I think most folks would still think you are trying to cut in even if the merge lane wasn’t being fully utilized because people tend to prioritize fairness over efficiency.

You must never drive south. Starting pretty much at the Beltway and going South, I often see miles of open valid lane that will eventually close. That’s what I’ve been talking about. Using the shoulder is illegal. This conversation started about a lane taken away by construction. In that situation, thinking that merging early is more fair is an illusion.

[KLizotte]

@dasgeh 59019 wrote:

In that situation, thinking that merging early is more fair is an illusion.

It may more inefficient from a through-put perspective, but it is fair because everyone is being inconvenienced equally. If efficiency were paramount, I’d be able to cut in front of you in every line because I’m faster.

[dasgeh]

@KLizotte 59021 wrote:

It may more inefficient from a through-put perspective, but it is fair because everyone is being inconvenienced equally. If efficiency were paramount, I’d be able to cut in front of you in every line because I’m faster.

That’s silly. It makes everyone spend more time in the car, contributes to more air pollution, drives up costs of … everything that relates to that stretch of road at that time. And everyone who is in the non-disappearing lane behind where you think I should merge (leaving open pavement) will go slower if I merge early. How is it fair to make me and everyone behind me go slower because some drivers want to merge early?

Those in that lane in front of me have the opportunity to get over and increase their average speed (and the average speed of everyone behind them).

[KLizotte]

@dasgeh 59028 wrote:

That’s silly. It makes everyone spend more time in the car, contributes to more air pollution, drives up costs of … everything that relates to that stretch of road at that time. And everyone who is in the non-disappearing lane behind where you think I should merge (leaving open pavement) will go slower if I merge early. How is it fair to make me and everyone behind me go slower because some drivers want to merge early?

Those in that lane in front of me have the opportunity to get over and increase their average speed (and the average speed of everyone behind them).

I can’t say I’ve ever seen that in real life; only people using the break down lanes/exit lanes. If true however, then why are you complaining? You’ve got a free, unused lane all to yourself allowing you to bypass lots of traffic. If people refuse to let you in when the merging lane disappears, then perhaps you’ve violated a social norm or they think it isn’t safe? More importantly, how is this argument any different from that of drivers getting furious when cyclists slow them down when they are taking the lane? Why should drivers have to incur the costs of slowing down because cyclists feel like going out for a joy ride utilizing vehicles that can’t keep up with traffic? Sure, bikes aren’t as polluting but cyclists could get exercise instead by walking/running on the sidewalk and they are the minority. I’m sure drivers get annoyed by events like kidical mass clogging up the roadways and parking lots.

And again, following your logic, the same could be said of people with strollers on metro. They take up more than their fair share of space, slow people down getting in/out of metro, screw up the flow on escalators, and are a safety risk in cases of emergency. Therefore, strollers should be banned (I’m sure lots of people would support this proposal during rush hour). It would certainly make the system more efficient. Drivers also shouldn’t have to slow down around schools either since that isn’t fair to them; safety *bah* – kids should be obeying the laws like everyone else and staying out of the road plus that its the parents’ responsibility to keep them safe, not the drivers.

Be careful what you wish for.

[mstone]

@KLizotte 59021 wrote:

It may more inefficient from a through-put perspective, but it is fair because everyone is being inconvenienced equally. If efficiency were paramount, I’d be able to cut in front of you in every line because I’m faster.

It’s not a fairness issue because it’s not fair for you to feel holier-than-thou because you moved over unnecessarily early.

[KLizotte]

@mstone 59043 wrote:

It’s not a fairness issue because it’s not fair for you to feel holier-than-thou because you moved over unnecessarily early.

But she is arguing that there is an unused lane; if people want to use it they can and therefore go faster. Therefore, if people are choosing to all bunch up in one lane and go slower then obviously that is their choice (though what is “unnecessarily early” is debatable and bound to vary from one driver to the next). As I said before, I’ve *never* witnessed an empty lane like she describes (and really don’t see how it could happen in real life) so I fail to understand why we are arguing about this very hypothetical situation. The closest I’ve seen are people trying to sneak to the front of the line by using a breakdown lane or using an exit lane – neither of which I condone from a safety and fairness point of view (though I can see how someone might accidentally use the exit lane). Also someone mentioned earlier that he doesn’t merge too late so as to not to be accused of being a jerk so I presume most drivers may be merging a little earlier than necessary so as not to be perceived as cutting in line. Wow, drivers are trying to be civil to one another? Perhaps drivers are not acting in the most efficient manner (e.g, zippering at the last minute) but how can anyone find fault with politeness on the road? Likewise, why do we have a problem with shoaling but not with the same behavior on the road which is what these hypothetical empty lanes with a few cars advancing to the start of the line sounds like? Perhaps shoaling is more efficient after all?

All I’ve been trying to say is that there are many situations – Cabi, highways, standing in line at the grocery store, etc. – where everyone has to wait their turn irrespective of whether it is efficient from a system perspective or even necessarily 100% equitable (dasgeh is the one who mentioned that it wasn’t fair to her that people were merging too soon). Sometimes technology can make things more efficient (exit metering for instance) but the rest of the time, people just have to suck it up for the good of humanity. If that means going slower on the highway for a while due to an accident or construction, so be it. It should also be pointed out that dasgeh proposed a perfectly reasonable and justifiable argument *against* allowing cyclists on the road (pollution, individuals causing others to have to slow down); I’m advocating for a far more consistent approach to all road users.

[KLizotte]

I knew I had read something on this a long time ago. From the Federal Highway Operations Dept (it’s a rather entertaining read – really!):

http://ops.fhwa.dot.gov/publications/fhwahop12012/sec2.htm

So You Think You Can Merge?

Are you a “profiteering” lane merger, who seeks only your own personal gain, or are you an “altruistic” driver who yields to others for the benefit of all? Are you an “early merger” (upstream of the point of confluence) or “late merger” (at the last possible moment)? Are you “left-brain” or “right-brain; ” Republican or Democrat; plastic or paper? In the end, there is no right or wrong, legally speaking. When and how one merges is more a study in human behavior, and less a study in efficiency.

Early Attempts to Direct Motorists How to Merge

When the Interstates were built in the 1960s and 70s there was often “instruction” by local engineers and the media of how to engage Interstate ramps, acceleration and deceleration lanes, etc. Of course, at that time, traffic was less congested on the whole, and the merging and diverging were essentially lessons in how to enter and exit Interstates. Academia has touched on queue theory, gap analysis, and related safety-oriented aspects, but none of these studies have focused much on educating motorists how to merge efficiently, unless one considers a “queue” or a “traffic stream” as an entity that can deduce instruction. Nevertheless, the academic community has essentially confirmed, via queuing theory and microsimulation that the discharge rate after the merge governs congestion on the segment. In layman’s terms, there is a finite capacity of the single lane downstream of the constriction. Very little of what happens upstream can refute the laws of physics; that only one vehicle can occupy the discharge space at a time; and in a jammed situation, the lead vehicle does so from essentially a crawl speed.

Excepting for some basic, generic instruction in states’ drivers manuals (“wait for a safe gap in traffic” – typ.) little has been done at the national level to educate drivers how to merge safely and efficiently, as compared to other national education efforts promoting seat belt compliance, school zone safety, traveler information, or pedestrian rights and practices. The perceived reason for this may simply be the expectation that there will always be drivers who feel they know best how and when to merge in a queue, irrespective of any instruction to the contrary. The altruistic view is to leave gaps, yield to your neighbor, take your turn but don’t force your turn, and generally don’t deny him or her entry into your lane. The more proactive view is to take first opportunity to cut in line, perhaps “line jump” to chase whichever line seems to be moving, and scuttle the principles of any orderly manner. Anecdotal evidence from many local traffic blogs and an Internet search finds strong sentiment from both camps as to why they think their method is best.

Merge Principles

How can we increase the efficiency of merging prior to the discharge point? In two words – be orderly. Not surprisingly, safety improves too. It is repeatedly shown that traffic is inherently safer when all vehicles are traveling at or near the same speed. Think of an orderly progression on a crowded escalator. Everyone is safely cocooned because they are going the same speed. Now imagine the bumping and chaos that would occur if impatient folks pushed past others.

Principle #1: “Go Slow to Go Fast” Sound familiar?

“Go slow to go fast” is an increasingly trendy expression in traffic circles. It speaks to the seemingly paradoxical idea that if we slow down the rate of our “mixing” we can get past a constriction faster. A well known example (actually the winning entry in a 2006 contest to demonstrate the meaning of “throughput maximization”) is the “rice” experiment. In the first case, dry rice is poured all at once into a funnel. In the second case, the same amount is poured slowly. Repeated trials generally conclude about a one-third time savings to empty the funnel via the second method. And, it should be noted, there is a tipping point reached as one graduates from a v-e-r-y slow pour, to a medium pace, and so on. What lesson does the rice experiment teach us about traffic? The densely packed rice (or traffic) in the first trial creates friction in the literal sense and the practical sense, respectively. The denser the traffic, the smaller the safety cushion around each driver, and the more cautious (i.e., slower) he becomes. A classic “bell curve” diagram also serves to explain how traffic throughput reaches an apex up to the point where traffic friction and conflict conspire to begin a decline in the rate of throughput and speed. There exist some examples of validation of this principle at intersections (e.g., traffic signalization, roundabouts, vehicle detection) that demonstrates that slowing or stopping some traffic benefits the aggregate flow, and is far better than the free-for-all converse. In the bottleneck and corridor genres, we have ramp metering and speed harmonization, respectively, providing examples on freeways.

Principle #2: Keep Sufficient Gaps

Keeping sufficient (or ideally, the largest possible) gaps leads to uniform and free(er) traffic flow. Gaps allow for small adjustments in braking, accelerating, and drifting. The larger the gap, the lesser the “ripple” affecting adjacent and following vehicles, which otherwise would react by slowing. Gap maintenance (and thus, lane reliability) is achieved on-purpose in high-occupancy vehicle (HOV) lanes or high-occupancy toll (HOT) lanes; by selective admittance in the former, and by dynamically shifting the price every few minutes in the latter. The target benefit is to allow qualifying vehicles the guarantee of a free flow trip, versus the hit-or-miss prospect in the adjacent general purpose (GP) lanes. Both cases have the added (and intended) benefit of removing vehicles and or person-trips from the GP lanes too; so all traffic streams win when these practices are employed. Absent out-and-out violators who can muck up the system, agencies can tweak the lane mandates to keep the systems running at optimum levels. How does this apply to localized bottlenecks? Theoretically, the same “gapping” principles would hold true in backups; to wit, leaving progressively larger gaps would allow for progressively better progression. (Taken to the extreme, no “bottleneck” would even exist!) The point is that in congested situations the constant brake-tapping in bumper-to-bumper traffic works to self-perpetuate the problem. No one can get much momentum before he or she has to react to the vehicle directly ahead or adjacent. The ripple effects are short, abrupt, and inefficient. The obvious problem with this is that human nature simply won’t allow for the patience and orderliness to make this work. The second that I create a sufficient gap between me and the car ahead, some “profiteering” lane jumper will fill it. Which is a nice segue into the next principle; zippering.

Principle #3: Zippering

Unlike principle #2, which is noted to be fairly impractical to expect, this one could easily be melded into our regular practice; namely, to take turns, or “zipper” merge at the front of the line. The fairness – and simple visualization – of this principle speaks for itself. And there is already precedence that we have been schooled in this; witness the “Yield” condition and many recurring locations where this is the unwritten rule; newcomers quickly adapt! Advocates of zipper merging are proponents of “late” merges; i.e., staying in your lane until the last possible moment and taking turns to get through the chokepoint nozzle. One enterprising fellow in California has gone so far as to adorn his car with a zipper graphic and messages promoting this method.

Is Murphy Right? Does the Other Lane “Always Move Faster”?

How many times have you observed (or seemed to observe) that “the other lane is moving faster” only to get into that lane and then watch the first lane move past you? Actually, you are at the whim of “observation selection bias” which essentially opines that one will selectively conclude a result only on the basis of a distortion of data; in this case, your distorted sampling of only the cars that are moving, and less so the ones that aren’t. So, does cutting in line help you?

Imagine two lanes of cars. The left lane (L) is the continuous lane and the right lane (R) is dropping. You are 6th in line in R lane. If everyone stays put and “zippers” then the zipper order is L, R, L, R, etc. Your neighbor to your left is 11th and you will be 12th to merge. If, however, you “early merge” and cut in front of him into the L line, then you will now be 11th to merge, the person behind you (formerly 14th) moves up to 12th, and you neighbor drops to 13th. You win. Your neighbor loses. But the guy behind you benefits most.

Now consider the same scenario except the zipper order is R, L, R, L, etc. In the orderly scenario you would be 11th and your neighbor is 12th. If you cut in front of him, the guy behind you moves up to 11, you are now 12th, and your neighbor is now 14th. You neighbor really loses (drops two slots) and the guy behind you (formerly 13) really wins; he gains two spots – again.

Congratulations! In both scenarios you have definitely improved the slot for the guy behind you! You may or may not have improved your slot. And in either case, you made your neighbor mad! And in the end, all the jockeying you have done may have been canceled by someone ahead of you. So maybe it’s better to leave Murphy’s Law to “anything that can go wrong, will” and let zippering be the fair and simple solution to traffic backups.

[Author]

Posts