Underground Automated Highways: Example Future Forecast

In wandering around the internet for information on Automated Highway Systems, I came across a great example of a forecast on high density urban transportation by the Acceleration Studies Foundation. The full forecast is available here (.pdf link) while the brief synopsis is available here.

I'm not going to go into detail about the forecast, but it focuses on the convergence of three technologies, Tunnel Boring Systems, Automated Highway Systems, and Zero Emission Gas-Electric Vehicles that will enable a network of underground highways in high-density urban areas. Tunnel Boring Systems have been becoming cheaper and cheaper (and apparently there is a Moore's curve for TBS too) where replacing elevated highways with underground networks will become cost justifiable in the future. That combined with Automated Highway Systems, already proven in prototypes, and zero emission vehicles (extension of current ultra low emission vehicles) will lead to underground highways in the future.

What may be more interesting is not the content of the forecast but the methodology of it. While it may seem like a simple combination of three currently existing trends, the full document goes through a detailed analysis and justification for each trend while referencing numerous studies and other forecasts (or projections). Although most of the document focuses on technological issues, it also touches upon social and political issues that may hinder the progress. I particularly found interesting the discussion on acceptable perception of accidents listed under Key Uncertainties:

"It is possible that early AH systems might reduce the average accident rate to lower than 1/5 previous rates. Yet even a quintupling of safety may not be enough for adoption in several societies. Those societies able to accept a measurable and declining level of "normal accidents" caused by these complex technologies will be able to realize the safety benefits of UAH early. Those who unrealistically expect perfection from their machines will labor under their less efficient and more accident-prone manual systems until they change their mindsets, or until accident rates finally drop to miniscule levels, which may take an additional decade or two of advancement in AH technologies. (Ideas, Perspectives, Proposals)"

The forecast also lists numerous caveats and potential deviations (under Potential Events, Wildcards and Key Uncertainties) which lists indicators that could influence the future. There's also an Alternative Scenarios section but I find this to be weak and only there to support the existing conclusion of the UAH.

I get the feeling (instinct) that we tend to see how technology and products exists today as a combination of certain trends (i.e. Moore's law, miniaturization). In hindsight, these historical views are clear stories that explain where we are, but in trying to take this into the future, what are the applicable trends and technology developments to consider? There are probably numerous other trends that we could combine to develop an equally convincing yet entirely different forecast for the future of transportation.