Answers 2025/2026
Identify the basic components of the economic base model and the role of economic injections
and leakages - ANSWERSConsists of two regions:
- Local economic region: investments and expenditures lead to consumption
- Expenditures and taxes
- Savings and investments
- Non-local market: leakages (imports) and interjections (exports)
- Ex: Grand Canyon, Las Vegas
Discuss the four eras of US transportation, and resulting impacts on urban form, commuting
patterns and mode share - ANSWERS-1800-1890: Walking/horse-car era. Omnibus (horse-drawn
cart) on rail
-1890-1920: Electric streetcar era. Streetcar suburbs, no horses, power lines instead; privately
funded
-1920-1956: Recreational automobile era. Assembly line/Model-T Ford, manually controlled
street lights
-1956-present: Freeway era. Limited access and increased suburban/urban growth
Results: automobile dependence
,Discuss the poor accessibility and high cost of mobility in contemporary US cities, as well as
resulting external costs - ANSWERSFewer options for walking. 17% of household income to
transportation.
External costs of transportation system that society pays for: air pollution, noise pollution,
resource consumption, & infrastructure impacts.
Transportation investments require funding through different fees:
- User fees (gas tax, toll roads, vehicle registration, public transport pass, weigh station)
- Non-user fees (lightrail, bonds, property taxes)
Describe federal, state, metropolitan planning organization (MPO), and local government roles
in transport planning - ANSWERSFederal gov. role:
- Funding (federal gas tax, highway trust fund) & Regulation (fuel economy, vehicle safety, EPA,
etc.)
State gov. role:
- State highway system- rural, interstate, + freeway (ADOT)
- Comes up with state-wide plan (updated every 3 yrs)
MPO role:
- Regional transportation planning; required for federal funding; lack power to implement; 20-
year visionary plan
Local gov. role:
- Parking requirements (plan for busiest day of the year- Saturday before Christmas), zoning, &
infrastructure upkeep/repair
, Transportation planner role:
- Determine traffic impacts
- Estimate future demand
- Evaluate/propose alternatives
Differentiate the purpose of traffic impact analysis, cost-benefit analysis, and National
Environmental Impact Act (NEPA) review - ANSWERSTraffic Impact Analysis purpose:
- Used to understand impacts of a situation on traffic flow and determine required mitigation
and who pays (large land developments)
Cost-Benefit Analysis purpose:
- Used to compare multiple hypothetical scenarios or future build conditions versus no-build
conditions.
- Also considers public agencies, users, & society at large
NEPA Review purpose:
- Used to assess environmental impact. If federal funds are required, this is required
Discuss the purpose of the 4-step Urban Transportation Modeling system, and the role of traffic
analysis zones (TAZs) - ANSWERSBoth are used to forecast future travel demands.
-4 steps: trip generation, trip distribution, mode choice, & route assignment
-Made up/aggregated by zones
Explain the traditional focus of transportation planning, and the associated problem of induced
demand - ANSWERSTo cope with demand, build more infrastructure
Supply-side planning is traditional (focus on infrastructure and systems management) but not
sustainable because adding roadways uncorks latent demand