Evaluating Alternative Operations Strategies to Improve Travel Time ...

SHRP 2 L11: Final Report
Scenario Drivers
The following subsections provide a summary of the assumptions of the scenario drivers related to
Alternative Future 3: The Pessimistic Scenario.
Climate
Expected changes in weather that are to occur over a 40- to 60-year time frame will occur much
sooner. Some of these changes and likely impacts are shown in Table 5.3.
Table 5.3 Pessimistic Scenario Climate Change Impacts
Category
Precipitation
Temperature
Ocean Levels
More Intense Weather Events
Impact
• Accelerated asset deterioration
• Increased incidence of flooding events
• Water scarcity and loss of winter snowpack
• Increased incidence of wildfires
• Shift in ranges of endangered species
• Arctic asset and foundation deterioration
• Increase in the frequency and severity of heat events
• Reduction in frequency of severe cold
• Inundation of infrastructure
• Increase in storm surge intensities
• Damage to assets
• Increased frequency of road traffic disruption, including interruption of
emergency routes
The best scientific evidence suggests that the annual frequency of serious hurricanes along the
Atlantic and Gulf coasts will be seven to nine hurricanes by 2030. This scenario assumes nine to
eleven. The expected increase in average temperature by 2030 is one degree Celsius over current
temperatures. Sea level rise is not likely to show significant change over the next twenty years and
it is assumed that it will not be a dominant factor in defining the climatic condition in 2030.
Finally, precipitation intensity and patterns are expected to change over the next twenty years, but
not significantly. Over the longer term (40 to 60 years), some parts of the country are expected to
experience more droughts, whereas others will be experiencing higher rainfall.
Economy
Recessionary forces will continue to keep growth in gross domestic product (GDP) low (less than
2% of the annual growth rate), with the possibility of inflation eroding the purchasing power of the
American consumer. The federal and many state government debts will remain high, resulting in
greater difficulties borrowing in the bond market. Although governments have used economic
stimulus packages aimed at investing in job-intensive projects, few jobs will be created and the
unemployment rate will be around 10%. Low economic growth will result in a decline in
disposable income for the average American household, resulting in a stagnant housing market and
continuing decline in international trade. Key industries, such as manufacturing and energy, will
lose economic strength. With the dismal economic picture, immigration will slow and overall
population growth will not reach the expected value of 325 million by 2030.
Energy
Energy costs will increase significantly, with much of this increase caused by declining shares of
foreign petroleum reaching American shores. In some cases, the fuel supply will be interrupted due
to unrest in source countries as well as targeted foreign attacks against pipelines and other parts of
the distribution system. Even with this increasing cost of energy, average household energy
consumption will decline negligibly. However, the cost of transportation will increase
ALTERNATIVE FUTURES Page 58