Monday, August 23, 2010

Transportation Kinetics

The laws of kinetic energy for a hot gas beautifully describe our default behaviors in the complex network of interconnected “pressure vessels” we call our transportation corridors. Small things that move slowly get whacked by big things that move fast. Either the meek learn to get the hell out of the way; or they get with the program, bulk up, and shift into high gear.

It’s really not much more complicated than that. Not unless significant numbers of “molecules” choose to behave as though they are responsible for the impacts of their momentum on other molecules. And if that happens – Whoa! The changes which occur could begin to seem…well, intentional. As though something like intelligence might be at work. We might even see some respect for the little guy. But more on that later.

First, why do so many molecules want to go somewhere else so often in the first place? Why aren’t they happy being where they already are? And why are so many of the places where they want to go located so far apart? Why isn’t “a” next-door to “b” more often?

Well, that’s easy! The more kinetic energy you pump into the system, the further apart things get pushed!! (Duh.) In fact our transportation network here in the USA is a fantastic system for continuously manufacturing “needs” for more – and bigger – and longer – high-pressure pipes. Which, in turn, continuously manufactures “needs” for more energy, more machinery, more development, and more land. It’s quite the positive-feedback loop: great for investors, businesses, units of government, and employment. Tax revenues grow; the DOT and other bureaucracies swell; and politicians buy votes with the pork they deliver to the Highway Lobby. Meanwhile society can avoid balancing current expenditures with current income. You could base a whole damned economy on it. For a while, anyway.

Back to my point. For various reasons, lots of people think there are serious problems with transportation. So let’s consider some of the “solutions” that are being proposed.

(1) The overwhelming majority seem to think the way to solve the problem is to expand the high-pressure pipe network. Well, “think” isn’t really the right word; it’s their default behavior that does the thinking…and the voting. That’s why their default solution is mostly about accommodating more and more big, fast molecules. True, many people SAY they want the small and the slow to have a fair shake, but they don’t really mean it. Momentum speaks louder than words.

(2) Some people – a distinct minority – believe that if enough low-pressure pipes are added to the network, most of the molecules will have a choice as to which pipes they use: high-pressure pipes if they want to be big and fast, or low-pressure pipes if they want to be small and slow.

It’s a nice idea, but there are serious problems with it. Maybe even insurmountable ones, especially if we are at all serious about the “most” having a “choice”. Why? The existing network consists primarily of high-pressure pipes. Even if we focus on areas where molecules tend to congregate, most are places which are richly interconnected with high-pressure pipes but poorly connected with low-pressure ones. Installing new low-pressure pipes parallel to so many existing high-pressure pipes would cost a fortune. Maybe even an empire.

So who would pay for it? If you consider where the big, fast molecules REALLY like to live (exurbia), you will find damn few low-pressure pipes. Why? Avoiding the costs of low-pressure pipes is one big reason why so many big, fast molecules move there! Not only that, but most of these upwardly-mobile molecules spend most of their time “off the reservation”, congesting high-pressure pipes in places where they don’t BEGIN to pay their fair share. The system is already bankrupt, running on IOUs from children who can’t even vote yet.

Then there is the matter of proximity. Fast molecules couldn't care less about destination “a” being close to “b” – ten or twenty miles seem mighty short when you’re really truckin’ down a high-pressure pipe. But pity the slow molecules! Even if there is a low-pressure pipe running parallel to a high-pressure one (so the slow guys don’t run the risk getting whacked), the TIME it takes can be a killer. Moving slow, it feels like darn near everything is just too far away.

Last, we must not forget that all parallel pipes eventually have to intersect. And it’s a tough engineering challenge to build these intersections so that the small, slow molecules can safely cross the high-pressure pipes. Especially when you have big, fast molecules who don’t much like being restrained. You know, high momentum dudes who behave as though having to wait for slowpokes is…well…an insult! “Move over, a**hole!!” “Get the f**k out of my road!”

(3) A few people have their fingers crossed that the energy supply for the high-momentum molecules will eventually dwindle; the pressure will go down in the high-pressure pipes; and somehow the system will become more “humane” for small, slow guys. Maybe they are right. Probably they are right. It might take a while, though. And it’s sort of weird, expecting pipes to get “humane”. Like “pipes” caused the problem in the first place! Meanwhile, it’s obvious that the energy supply for the big and fast hasn’t run out yet. So many of the folks who are waiting for the dwindling conclude the best they can do right now is to buckle up themselves and their kids inside a big-ish molecule too. OK, one that’s not-so-big…but not-so-small, either! Then if they get whacked by a really big, fast molecule, it won’t be a guaranteed death sentence.

(4..?) Might there be another possibility – one which doesn’t require huge numbers of additional pipes…or…having to run out of energy? Like, what would happen if millions of molecules…just…began to choose to have less momentum more often? Hmm…maybe when we brush our teeth tonight, we could look in the mirror for clues about how to make it happen.


coolynn said...


Tom Street said...

It is clear that the "coexistence" approach is flawed. The amount of pipe space for the big molecule flows needs to be dismantled or transferred to the little molecule flows. It is just too easy to just jump in your car and go.

Anonymous said...

The highpressure-pipes themselves are constructed from molecules that have traveled thousands of miles.

Beth said...

My understanding of thermodynamics says that disorder in the universe is always increasing. We humans seem to be accommodating that disorder with each car-centric transportation decision we make.

Also, as relates to transportation kinetics, the higher speeds we go in our vehicles, the more energy we need to use to overcome air resistance. At a velocity of 67 mph, the force of air on the front of the car will be about 500 lbs. At this velocity, more than 50% of gasoline in a car is used to create the force to overcome air resistance. But slowing down could make a difference. I think it is something like at 1/2 speed, air resistance is 1/4 strong. That means that the vehicle uses 1/4 as much fuel to overcome air resistance when it slows down. So, slowing down would buy us many more miles per gallon.

Considering that in a typical automobile about 80% of the energy in our gasoline engines is wasted as heat, we really can't afford to make things worse.

Bicycles, with their slower speeds and smaller sizes, do not have to overcome this gargantuan force, so have efficiencies built in to allow muscle energy to counteract the air resistance.

Conclusion: The laws of thermodynamics trump the laws of convenience. We will and are suffering for our lack of understanding, compassion, and discipline.