Wednesday, September 07, 2005

Flexibility vs. The Monolith

It occurs to me that in at least one way New Orleans was a modern city, before Katrina. A relatively large percentage of the population did not own a car. They relied on public transportation, and that system failed them completely when disaster struck. Families with private cars had the option of evacuating before the storm. Those without had to stay - and we've all seen the results. Of course, for many of these families the lack of private transportation wasn't really a choice. They simply could not afford to own, maintain or operate private vehicles. But surely some could and didn't, for various reasons. And these people not only trapped themselves by their choice, but trapped others they might have been able to help escape.

Reliance on private vehicles for primary transportation has drawbacks. It's expensive. There are significant environmental consequences. Traffic congestion can be a problem. Roads are expensive to build and maintain. It's important to remember, though, that there are corresponding advantages. Among them are flexibility and survivability. Disaster planning includes systems hardening, and that means identifying and mitigating intersystem dependancies. Public transportation can fail catastrophically in many ways. Look at the pictures of flooded city buses in New Orleans, for one great example. Sure, there are thousands of flooded and useless private vehicles in New Orleans also, but since private vehicles aren't concentrated into a few areas during downtime, they are far less likely to suffer the same kind of percentage attrition that the public buses are. They also don't rely on a cadre of professional drivers to be useful - drivers who may be unavailable during disaster scenarios.