PRT Enthusiasts ignore two critical pots of information when evaluating future transportation needs: Peak Oil and Climate Change.
Our transportation choices are influenced largely by two factors: perceptions of convenience and relative cost. Right now, private automobiles are the cheapest, most convenient mode of transportation for more than a mile up to several hundred miles of travel. Therefore, most people buy and use private automobiles and eschew public transportation.
Peak Oil and Climate Change are raising the cost of everything. During the past spike in gasoline prices, private automobile traffic declined precipitously, as did transport by truck. Cargo ships are still travelling at 10 knots rather than their earlier 24 knots to save fuel. As gas prices return to $4.00 per gallon and beyond, more people will leave their cars at home and travel by foot, bicycle and public transportation, all without the expense, energy consumption and urban blight of building a PRT network.
As climate change takes hold and global agricultural patterns change, precious fossil fuels will be reserved for moving food and water about the planet rather than people. Localism is already seen as the response to climate change, as we seek ways to grow our own food within easy transportation distance from our communities.
All this will change public attitudes about transportation, as we all pull together in mutual aid to accommodate the coming changes. PRT fosters individualism, on demand services and elitism, all of which are antithetical in a world demanding local cooperative solutions.
PRT is a 20th Century solution to a 21st Century problem