Fun with My Tracks, an accident, and Biking in Davis
After wandering off the Bike Loop a bit, I decided to head home. I was biking down Russell Blvd., and I witnessed a very scary car accident. The accident happened where I stopped recording the track, at the red marker. A guy in a cherried-out lifted F-150 was sitting at the traffic light (that's the point where I turned around). When the light turned green, he floored it. According to the other witnesses, he was racing with someone, or trying to catch someone who had cut him off. I couldn't see the other car because it was behind his gigantic stupid truck.
What I did see, though, was that he accelerated continuously until he reached the next intersection (the red marker), where he had a head-on collision with a girl in a 1990's Honda Civic trying to make a left turn. His engine was deafeningly loud even a block away, and I heard it roaring and down-shifting right up until the crash.
Looking at the damage to her car, it looked like he basically ran it over. The lift kit on the truck put his undercarriage about level with her roof, and there were even little ladders installed to climb up to the doors. After he ran over the Civic, he swerved around a bit, jumped the median, sideswiped a small SUV in the oncoming traffic, spun 180 degrees, and snapped his axle. When the axle snapped, I heard his engine redline for half a second and then cut.
Happily, nobody was hurt. The girl in the Civic was pretty much petrified, though. She was convinced that the accident was her fault because she didn't get out of the way.
I told her this was nonsense; the truck was going more than double the speed limit, and I'm pretty sure he didn't have his lights on (it was dusk, but not completely dark yet). She asked me about five times, "How much do you think it will cost to fix?" I told her, "Cost you? Nothing. He was committing maybe a dozen moving violations, and probably racing someone. His insurance company will probably be so happy not to have to pay medical bills that they will buy you a whole new car."
Maybe she could have been a little swifter completing her turn, but it's a busy street and there is a lot of pedestrian and bicycle traffic (it parallels a bike path). Making a quick turn is probably not a good idea. Or, maybe she could have waited until this asshole passed, but, as I pointed out, he was going maybe 50 or 60 in a 30 zone, and accelerating. She timed her turn right for reasonable traffic flow, but didn't account for total maniacs among the oncoming traffic. It would have been difficult to judge when he would reach the intersection she was turning through.
Oi!
As it turns out, Davis has been thinking about redesigning this stretch of Russell Blvd. for several years. If you look at the proposed design, it would have made this accident impossible or unlikely. You can't race on a one lane road, and a landscaped medium would have prevented the second collision.
A Prisoner's Dilemma
I encountered these two defectors in an extremely crowded parking structure in Old Town Pasadena. This isn't just antisocial behavior. The owners of these two titanic vehicles are also breaking the clearly written rules.
It occurs to me that the decision to buy these vehicles in the first place can also be modeled using many, many iterations of the Prisoner's Dilemma played against every other driver. Here's how such a model might be constructed. The options are :
- Buy an SUV (defect)
- Buy a compact car (cooperate)
In a single round of Prisoner's Dilemma, it is usually reasoned that the only rational choice is to defect. However, when two individuals play many iterations against one another, more interesting strategies can succeed. The strategy that seems to do the best in most situations is some variant of generous, randomly forgiving tit-for-tat. To apply the Prisoner's Dilemma to the automobile market, you must view the game as continuously ongoing because a player can trade in their car for a different model at any time, and the game is played against every other driver on the road. Each iteration makes a marginal contribution to the total outcome for the player. For example, the actual risk of death is the sum over the marginal risk of death arising from the outcome of each game.
The outcomes are :
| Player's Choice | |||
| defect | cooperate | ||
| Stranger's Choice | defect | Punishment for Mutual Defection Both players buy an SUV, negating the advantages of owning a larger vehicle. Both players are penalized with substantial marginal increases in traffic congestion, gas prices, risk of death, risk of injury, and rate of damage to shared environmental resources. |
Sucker's Payoff Player suffers moderate marginal increase of gas prices, traffic congestion, and rate of destruction of shared environmental resources than the Punishment for Mutual Defection. However, the player suffers a worse view of the road and substantially increased marginal risk of death and injury. |
| cooperate | Temptation Player suffers a moderate marginal increase of gas prices, traffic congestion, and rate of destruction of shared environmental resources than the Punishment for Mutual Defection. They also enjoy better view of the road and a substantially reduced marginal risk of death or injury. |
Reward for Mutual Cooperation Both the Player and the Stranger enjoy a better view of the road and substantial marginal reductions in gas prices, traffic congestion, rate of destruction of shared environmental resources, and risk of death and injury. |
|
In computer models of the iterated Prisoner's Dilemma, and in real-world situations are well represented by the model, strategies that are "nice," "generous" and "forgiving" tend to thrive. These terms have a technical meaning here. "Nice" simply describes a strategy that will not defect first, "generous" describes strategies that will not retaliate against other players when they defect under some circumstances, and "forgiving" describes strategies that will "forget" about past defections of other players. Richard Dawkins describes this in some detail in The Selfish Gene (see Chapter 12: Nice Guys Finish First), basing much of his argument on the research of Robert Axelrod.
If the automobile market really can be modeled using the iterated Prisoners Dilemma, then we would expect to see the most successful strategies in Axelrod's tournaments, which are mostly "nice," become the dominant strategy for car-buying. That is to say, we should see mostly compact cars. So, why do people keep buying SUVs? They are playing Defect against the rest of us, hoping to receive the Temptation outcome from most of the iterations of the game.
This is especially curious because because both the Punishment for Mutual Defection and the Sucker's Payoff are very severe. It doesn't take very many people playing Defect to block the view on the road, to drive up gas prices, to dramatically increase the risk of death an injury for all drivers, and to accelerate the rate of destruction of our shared environment. The Reward for Mutual Cooperation should be a very strong attractor in the problem space.
It's very tempting to think of SUV buyers as stupid, or as assholes, or as sociopaths. However, it is more useful to model the decision as a purely rational decision based on what they think will be the best strategy. For most people, it probably isn't a rational choice, but that doesn't actually matter. In the model, we pretend that the players are playing as if they are making rational choices. This is how computers play Prisoner's Dilemma, even though they aren't capable of rational choices.
Game theory offers a fairly convincing (and rather grim) explanation for the phenomenon of SUVs. It makes less sense to play Cooperate if you don't think the game will go on for much longer. On the last round of the game, it becomes the classic, non-iterated Prisoner's Dilemma for which the only rational choice is Defect. Everyone knows that we're running out of oil. Consciously or unconsciously, people are behaving in a way that suggests that the shadow of the future is shortening.
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