Evaluating Alternative Operations Strategies to Improve Travel Time ...

SHRP 2 L11: Final Report
transportation will increase because of (1) a stronger economy and increased employment, (2)
pressure for efficiency coming from climate change and energy constraints and regulations, and (3)
emerging technologies making more-reliable transportation systems feasible.
Scenario Drivers
The following subsections provide a summary of the assumptions of the scenario drivers related to
Alternative Future 2: The Mediocre Scenario.
Climate
Global warming will continue, bringing slightly higher temperatures, rising sea levels, and some
coastal flooding. Rare events, such as heavy rains and snows, hurricanes, and tornadoes will
become more frequent. These will affect transportation infrastructure, bringing about more
unexpected failures and service interruptions. Interruptions in electric power will be more common
(until transmission infrastructure is renewed and protected). This will impact traffic-management
systems and the ability to recharge electric vehicles. Under this scenario, the climate is not
expected to reach a tipping point, but it may be on or near the borderline.
Economy
The economy will gradually rebound from the current recession and enter a period of moderate
economic growth, during which GDP will increase at 2 to 3% annually over the next twenty years.
Employment will grow and the unemployment rate will return to normal levels (5-7%). Through
mostly immigration, the population will increase at about 0.9% annually. Together, these
demographic trends will lead to increased travel demand, measured in vehicle miles of travel.
Vehicle miles of travel will increase annually at a rate of about 1.5%, as a result of population
growth, moderate energy prices, and reasonable transportation services.
Energy
Energy costs will increase slowly after 2010, with much of this increase caused by declining shares
of foreign petroleum reaching American shores. Gasoline will be in the range $3 to $5 per gallon.
Electricity prices will also rise gradually, pressured in part by the gradual shift toward more
electrically-powered vehicles.
Responding Trends
The secondary effects of this scenario are determined by assessing how current trends and factors
will be affected and will respond to increasing rare weather events, moderate increases in
employment and population, and an increase in energy prices.
Demographics and Land Use
• Future growth will be dominated by more-compact urban development, infill, downtown
regentrification, and revitalization. These trends will be supported by social services and
public infrastructure investments to make cities more livable. However, as long as travel
service and prices are reasonable, some spreading of cities and settlement in rural areas will
continue. The trend toward spreading of cities will be supported by communications
technologies in the form of telecommuting and ecommerce. These trends will result in
more reliability in cities and less reliability in rural areas.
Technology
• There will be continuing deployment of available ITS technologies for incident detection
and management, signal coordination, and freeway corridor management. These will
primarily be current and emerging technologies that will see widespread application.
ALTERNATIVE FUTURES Page 54