Two thoughts from wandering around Phnom Penh by foot, moto and tuktuk.

Being a good driver

What does it mean when you call someone a good driver? There are really three components to being “good”:

  1. Values: You are making an appropriate tradeoff between speed and safety.
  2. Ability: a package of skills that expand your speed-safety possibility frontier (more safety at the same speed, or more speed for the same safety).
  3. Adaptation: How well can you predict what other drivers will do? How well can they predict what you will do?

We talk about being a good driver as though it’s just #2, but usually in the US I suspect it’s about #1. Or, maybe one of the skills in #2 is “accurately assessing risks” and when someone is a bad driver they may not realize accurately what tradeoffs they’re actually making.

When travelling, people often say things like “the drivers here are terrible.” And there may be geographic variation in #2, but more of it is probably #3. Being a good driver is tied up in your deep knowledge of local driving behavior, and how well you match other drivers’ mental models so they can anticipate what you will do and act accordingly.

This framework applies to many things in life.


As a cyclist in the US I noticed that I was often frustrated with cars but never had a problem with buses. Buses were so big and slow-moving that they were easy to circumvent and avoid. Like in the natural world, things that are too removed from you in scale are just not direct competitors. They occupy different niches.

Here in Phnom Penh things are similar. There are three common vehicle classes: motorcycles/scooters, tuk-tuks, and cars/SUVs. Cars are so big and bulky that it’s easy to get around them on a moto, but tuk-tuks are just the right size to always be in your way whether you’re in a car or on two wheels.

This is similar to the social phenomenon of “the narcissism of small differences”: the closer someone is to you, the more they compete for the same resources, and the more threatening they become.