Evaluating Alternative Operations Strategies to Improve Travel Time ...

SHRP 2 L11: Final Report
economic, population, and employment growth, and 2) new technology making more reliable
transportation systems feasible.
Scenario Drivers
The following subsections provide a summary of the assumptions for the scenario drivers related
to Alternative Future 1: The Optimistic Scenario.
Climate
In addition to addressing greenhouse gas emissions at lower-than-expected costs through new
energy technologies, the impacts of weather trends associated with climate change are not as
severe as expected. Occurrence of rare events such as extreme rains and snow, hurricanes, and
tornadoes, will remain consistent with historical patterns.
Economy
Technological advances and relatively stable energy prices lead to strong economic growth, during
which GDP will increase at 3 to 4% annually over the next twenty years. A new “clean” energy
industry will result in population and employment growth coupled with a drop in unemployment to
below-normal levels (4-5%). These demographic trends will lead to increased travel demand,
measured in vehicle miles of travel increasing at 2% annually.
Energy
Innovative and alternative clean-energy technologies will be developed and rapidly adopted to
address global energy needs. As a result, energy prices will stabilize and the cost of addressing
climate change is less than expected.
Responding Trends
The secondary effects of this scenario are determined by assessing how current trends and factors
will be affected and respond to a moderate climate, strong economic growth, and stable energy
prices.
Demographics and Land Use
• As a result of stronger economic growth, population growth will remain high, particularly
through immigration.
• The aging population will phase out of the labor force and into retirement, continuing the
aging-in-place phenomenon. Economic growth will have a positive effect on retirees’
wealth, resulting in stable VMT per capita for the aging population. Furthermore, advances
in medical technology, including both prosthetic and genetic technologies, are likely to
increase both life spans and human performance as a function of age. This would keep
more single-occupant vehicles on the road, putting a floor under demand because the total
driving population will be growing.
• Through affordable travel and a continued trend of urbanization with population growth
occurring in metropolitan areas, spreading of cities and settlement in rural areas will
continue. This trend will be supported by communications technologies which facilitate
telecommuting and ecommerce.
Technology
• Considerable increases in the capability and application of imbedded sensors in all aspects
of life are anticipated. For the transportation system, this means access to low-cost, highaccuracy
data on component performance and condition. This would enable a complete
understanding of network conditions, congestion, and incidents. The rapid advancement of
ALTERNATIVE FUTURES Page 51