Thursday, September 3, 2009

Still Alive, Still Pessimistic (Traffic)

In normal circumstances I would apologize for my 9+ months absence from the realm of the blog, but having been rather thoroughly convinced that I am my only reader, I hereby forgive myself for the delay in advance of any apology and will post what I want to post here without further ado.

There have been many things that should have warranted a blog post so far this year, and yet I haven't had either the time, energy, or desire to sit down and construct a legitimate post that is up to the high standards of my reader(s), namely, myself. In some idle minutes the other day, however, I checked the link to the blog and began reading some of my older posts which are, while outdated, still fun to read and utilize valid logic and argumentation. So it's inspired me to revist the blog realm and hopefully stay a little bit more up to date. I certainly do want to finish my auction post at some point, and get back to talking about economics issues. Today however will be more of a continuation of my traffic complaints having a year's worth of commuting under my belt to add to my traffic "expertise." And so we begin.

As many trains of thought do, this one begins out of frustration (or to use a business cliché, "sensing an opportunity"). I see many many failures of my "Golden Rule" every day, which is disheartening, and to add insult to injury I got a speeding ticket a while back trying to get out of a situation where I was "boxed in" before I missed my exit. Even so, the worst part of my week is sitting in stop-and-go traffic for 20 minutes, only to have it magically clear up a couple miles down the road. Although some may say, don't question your blessings, perhaps it is the commuting pessimist in me that suspects the slowdown itself never should have happened. Time to flip on “analyst mode” and think about the problem.

Before even identifying the problem, I can tell you what is not the solution: metering lights. Allow me to vent just a moment here before coming to my ultimate point. Metering lights do nothing productive. I'm not sure who invented them and, worse yet, who voted them into the state legislation, but it was probably someone who has a very shortsighted view of either traffic congestion and/or simple economics (California politicians? Economic neophytes? What a silly suggestion!). There is no scenario that I have witnessed where metering lights have done anything other than cause congestion on the onramp. The congestion never helps the situation. Either the highway is already congested, wherein the metering lights merely transfer onramp congestion back a few feet from the merge lane to the line on the onramp with the stoplights, or there is no congestion on the highway and the metering lights create ridiculous congestion on the onramp for no reason. Some may claim that this second scenario is the point of metering lights ("hey, if we didn't have em, there WOULD be congestion on the highway!") but that is pretty ridiculous. Assuming people aren't idiots when merging onto the highway (granted, a surprisingly large caveat), the additional traffic would not cause much if any delay for the highway traffic. In any event, the societal lost time would be less than having to sit through 3 minutes of metering lights for the person entering the traffic system. Not to mention it's bad for mileage to have to come to a complete stop unnecessarily so as to "obey the law."

Ok, I feel a little bit better. The point of bringing up the metering lights is that they are evidently the government's solution to making traffic better. Naturally I've brought up my concerns before about inefficient government intervention, and here is a nice, bottled-up, everyday scenario for us to use as evidence of that fact. Metering lights, which taxpayers were forced to pay for, do not solve the problem and in fact only have the potential to make matters worse. The government failed us, and now we're stuck not only footing the bill but putting up with this incremental waste of resources until who knows when. Yay.

With a year's worth of commuting and traffic experience as well as all my past endeavors into the forays of theoretical economics combined with time spent amidst frustrating traffic systems, I took it upon myself to think about, aside from not following the "Golden Rule," why these mystery slow downs occur. It should not surprise my readers to discover my conclusion: more idiot drivers.

We all know about the phenomenon I call "the brake chain" (I'm developing my own traffic language here, aren't I?), where one driver on the highway brakes for whatever reason, sometimes for a safety concern, sometimes because they just aren't paying attention, sometimes for no logical reason whatsoever. The red lights cause the driver behind him to brake, which cause the driver behind HIM to break, etc etc. Depending on several factors including but not limited to how dense with cars the traffic system is, the brake chain can continue on for a good several minutes. Other things that can affect the duration of the brake chain: beginning speed (going faster means the speed-reduction effect of a brake chain is more severe, due in part to safety concerns), and following-driver ignorance/miscalculation, as drivers tend to over-brake also out of an inflated concern for safety.

During peak traffic times, aka "rush hour," these brake chains can be very disruptive, as traffic density is at the daily peak. The only way to break the brake chain (forgive the homonym) is for the numbers of cars entering the brake chain to be less than the number exiting the brake chain. At peak commuting times, if we assume traffic starts at speed limit speeds, you have cars entering the brake chain system going 70mph, and cars exiting the system at 50mph, then accelerating back up to 70mph. However, this creates a problem, as there will be more cars entering the system than exiting the system until overall traffic density (in other words, cars per minute, for example) drops below the traffic density of cars exiting the system. Only then can the system improve, and during rush hour, it can take a long time for that density to drop, and a longer time depending on how slow the brake chain drops the speed of traffic.

This explanation can be confusing, I understand, so here's a simpler way of explaining it: if someone brakes on the highway, and there are a lot of cars on the road, most likely the person behind him will brake as well. The subsequent cars will brake behind the cars in front of them, creating a chain of cars who are braking, lowering the speed of traffic. The cars that brake will then need to re-accelerate back up to their original speed, but in the meantime, looking at the highway from a helicopter's point of view, for example, there will be this patch of road where the speed has dropped due to the "brake chain" More cars will be entering this patch of road (going the original, fast speed of traffic) than will be exiting the patch (going the new, slower speed, and re-accelerating), and so the patch of road that is slower will grow longer as long as the total cars entering at the faster entry speed exceed the total cars exiting at the slower exit speed. Hopefully that's a little bit more clear.

To make matters more difficult, it is extremely difficult to manage one's way out of this system without just having to deal with it (i.e. without waiting for "market conditions" to improve). Further driver error can have the same effect as the initial brake chain, as now if anyone brakes too much and drops the brake chain's speed to 45 mph, that is now the new speed of the system for everyone behind that person. A chain is only as strong as its weakest link, as the saying goes, and weak drivers impose the traffic cost on all of us. This is why a slight brake chain can, several minutes down the line, create a traffic jam that slows the speed of traffic to a grinding halt possibly even below 10mph.

The most disgusting part of this realization is that the true culprits, the drivers that slowed down first, are not the ones that bear the cost of their error. The first driver, who tapped his brake for no reason while traffic was at the original, fast speed, creates the system but is instantly the first person to exit the system. That system that is left in his wake will exist, and will likely even get worse until overall congestion conditions improve (which may take hours), and his commute time will be hardly affected. The same goes for every driver who slows down the speed of the brake chain: he will be the first to exit the system which now contains the slower speed, but he will have created that system for everyone behind him. Doesn't it seem immensely unfair that 99% of the time (made up number) when you're sitting in a traffic jam, it's probably the fault of some half wit who, by the way, did not even have to sit through his own traffic jam? Boom. Market failure. See, didn't you have a feeling there was one lying around? I hope that every single traffic expert out there has reached the same conclusion (obviously not though; we have metering lights...)

Unfortunately, there do not seem to be easy solutions to this market failure that come to mind. How do we shift punishment away from innocent drivers and place it on the culprits? It is also unfortunate that the error can only take a few seconds to have hours of repercussions... it is easy to see that there was an error made, but impossible to trace it back given our current technology. Perhaps in the future if, for example, we have every mile of highway videotaped, or on-board computer systems that can track every single car on the highway, we would be able to trace back traffic jams to the bad drivers who caused them, but until then, I think we're just stuck with the plea that, if you are on the highway, please do not brake unnecessarily. Any significant speed reductions or even perceived speed reductions (tapping on your brakes puts the driver behind you on edge) can cause long traffic waits for EVERYONE behind you. Of course if you're reading this and this is news to you I'd also beg you to read my "Golden Rule of Commuting" post, as that will also provide some good insights on efficient highway driving.

Thanks for reading, if you did read. Hopefully I'll keep on updating. Following my blog (on the right hand side of the page, probably back near the top) will provide a good incentive for me to entertain an audience, so if you like what you read, follow or comment so that I know I'm not my only reader :).