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Comment by CraigJPerry | Hacker News Reader

That's a kind of brute force approach. It seems sub optimal but I don't know how to reason about it.

Should I say that observing every vehicle across the median on the oncoming carriageway is inefficient? Well I can't say that because occasionally some small cargo or even a wheel falls off and bounds across to the oncoming lane - something you definitely want to see coming.

Perhaps taking a zonal approach is as effective and certainly less taxing on the driver.

Scan each zone, some zones get scanned more frequently, and look for anything unusual.

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Defensive driving is really just a specific application of situational awareness [0]. With practice and experience you'll go from just maintaining visibility and space for reaction time to actually remembering where drivers are that have been blocked from your view by other vehicles. You never really track every vehicle and pedestrian, but you do make note of particular ones and the rest get lumped into groups based on their behavior. You'll learn to anticipate the car that's going to make a left turn in front of you by taking your foot off the throttle earlier instead of braking at the last second.

[0] http://en.wikipedia.org/wiki/Situation_awareness

you're talking about chunking: at first you try to remember everything, then as you gain experience you learn you can abstract certain items away to a general model of them (chunk) without having to remember the specifics of each individual item.

Like everything related to driving, it eventually becomes automatic.

It's not that you're consciously looking at each car and saying "Is this car going to be a problem? Is this one a problem?" Instead, you recognize patterns. If a car suddenly weaves out of its lane, it triggers a tinge of fear and you give that car a wide berth until you can pass him and leave him behind. If you see brake lights go on 10 cars ahead of you, you know that you're going to have to slow down, so get ready for it (oftentimes, I'll let up on the gas as soon as I see brake lights go on a quarter mile down the road, and by the time I get to the traffic, I'll be going their speed anyway). If you're in a car's blind spot, pay extra careful attention to turn signals or any deviation from his lane, and try to pull forward or behind so he can see you. If a car is clearly in a rush, it's a good bet he's going to weave in front of you, so hang back and make sure you have room to adjust if he does. If two cars try to enter the same spot in the same line (this is my personal biggest fear, they're both in each other's blind spot and each has reason to believe the lane they're switching into is clear), hang back, and honk if it's clear that they don't see each other.

It's about pattern recognition, knowing which situations are dangerous so you can be extra careful whenever it looks like one of those situations is happening.

"That's a kind of brute force approach. It seems sub optimal but I don't know how to reason about it."

Well, what else are you doing while driving?

For the most part, whatever your answer is to that question, stop it. (Reasonable exceptions apply; conversation with another in the car isn't too big a deal, of course.)

Now that you're just driving and not doing anything else, you might as well be active about it and be on the lookout for long-tail risks, since really long-tail risks are all you ever have to worry about. Driving is fairly safe and almost everything that ever happens bad is long-tail in the first place or we wouldn't drive.

Agree 100% with "if you are doing something else while driving, stop it". I have always thought the conversation is the distracting part, not the act of holding a phone to your head. Research shows that it's less distracting to talk to a passenger than a phone conversation: http://scienceblogs.com/cognitivedaily/2007/01/24/want-to-dr... (link in article). Still, I prefer to remain focused on the driving conditions.

I'm not sure I agree that "driving is fairly safe" though. We have mitigated much of the risk associated with driving with vehicle impact standards and road design. I still really feel that most drivers don't understand the magnitude of what they are doing - they become accustomed to the relative safety and start doing other things. It seems the more safety we "build into the system" the more risks people are willing to take. I'm not suggesting we take safety out of the system though!

A zone won't hit your car...another car will.

Some things need to be brute forced.

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