sexta-feira, abril 04, 2008

Critical mass for mass transit

According to an article in the Economist (29-March-2008), Los Angeles is discovering the importance of "transport-oriented development" and is looking for "elegant density" along express bus routes and subway stops.

Elegant density may be an Hollywood concept difficult to translate into economics, but the synergies between urban transport and urban land use planning are easier to understand. Most urban "mass transit" schemes are viable for heavy traffic corridors with relatively high residential population density.

The same is true for other infrastructure networks, like water or electricity. A low density network has a higher cost per user than a high density network. That's why low density rural or far suburban networks with few users often require taxpayer subsidies.
In general, it is important to minimize the dimension of the infrastructure, and the investment cost, while serving the maximum number of users. With lower investment and more users and user fees, the more viable and self-sustaining the public service project.
There is in fact a minimum "critical mass" needed to justify most "mass transit" and transport infrastructure.