A two-part Delphi Survey was given to transportation experts attending the Asilomar Conference on Transportation and Energy in 2011. The survey asked respondents about trends in the US transportation sector in 2030, including alternative vehicles, high speed rail construction, rail freight transportation, average vehicle miles traveled, truck versus passenger car shares, vehicle fuel economy, and biofuels in different modes. Responses varied considerably, with respondents agreeing most strongly that rail infrastructure in 2030 would be similar to what exists today. Variations in responses reflect the fact that questions addressed complex issues which are subject to many uncertain factors
