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Memes for Good Driving
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Other Thoughts (2)
Right of Way
Wait and See
Who Is Passing Whom?
Preserving OptionsThe idea of preserving options, or of keeping your options open, isn't one that applies very often in driving, but when it does, it's good to know about.
The idea applies in various situations, but as with many other ideas, there's one particular situation that always reminds me of it. Say I'm on a three-lane interstate, and I'm out in the middle of a bubble, happily away from all the traffic. But, looking behind me, I can see that the barrier is breaking up … the slow cars are finally getting out of the way, and the irritated fast cars are starting to boil through. Imagine I'm in the middle lane, too. Sometimes in that situation I'll be in the right lane, but if I got through the barrier on the left, and already moved over once to leave a passing lane open, sometimes moving over twice seems excessive. Finally, imagine that the exit I want is coming up, and that I don't know which side it's on … which implies that I'm in or near a city, otherwise it would almost certainly be on the right. So, maybe I'm traveling somewhere, and the interstate is unfamiliar, or maybe it's just one of those exits I can never remember about.
I did say it was a particular situation, didn't I?
So, what should I do? I can't change lanes, because I don't know which side I want, but I can't just sit there, either, because then I'd soon have cars speeding by me on both sides, possibly cutting me off from the exit. I need to do something to keep my options open, and in this case, the thing to do is speed up, so that I can see the exit before the cars catch up with me.
I like to imagine that I'm in pole position, although it's not really the same thing.
Now, here's another generality for you. The reason that the idea of preserving options doesn't apply very often is that it requires a situation in which there's uncertainty, so that you don't immediately know which option you want to pick.
In the example above, the uncertainty came from not knowing the roads, but that's not the only place it can come from. It could, for example, come from not knowing the state of the traffic. Several years ago, there were a few months where I had a long commute. In the absence of traffic, the fastest route was straight down the highway, but during rush hour the highway would often (but not always) completely jam, and turn into miles and miles of stop-and-go traffic. In that case, the fastest route was to take this one exit and go around. Eventually I think I ended up always taking the exit, but for a while I tried to be flexible by getting into the right-hand lane to keep my options open and then not deciding which way to go until the last second. (The traffic was often backed up all the way to the exit, so I could see by direct observation whether it was jammed.)
Uncertainty can also come from not being able to judge relative speeds. The situation I described in Wait and See is a good example of that. If you stay in the left lane, you can keep your options open until you know what to do, but if you change lanes, car C might move forward and cut you off, in which case you lose the option of going first.
That suggests another general point. One reason you don't want to have another car sticking to you or hovering near you is that it interferes with your options by preventing you from moving in a certain direction. Conversely, if you're stuck in dense traffic, and there's a pore in an adjacent lane, you want to try and stay next to it, because it enhances your options by allowing you to move in a certain direction. (If you can't stay next to it, then it's expiring as an option, and you should quickly decide whether or not you want to exercise it.)
What's the value of a pore as an option? Well, a pore lets you change lanes, so it's useful as an option any time you're not sure what lane you want to be in. In particular, it's useful any time there's asymmetrical congestion, when the lanes are moving at different speeds, and you're not yet sure which lane is moving faster.
I'm sure there are plenty of other places that uncertainty can come from, but I think that ought to be enough examples to give you an idea of how uncertainty and preserving options fit together.
Go with the Flow
@ June (2004)