EE_Midterm Review_W25

PA 155 Economics and Equity in Transportation Systems and Policies Mid-term Review

Date: February 25, 2025

Instructor: Tierra Bills, Assistant Professor, Civil and Environmental Engineering & Public Policy, UCLA

Exam Structure

• Date: Thursday, Feb 27th

• Format: In-person, 1-hour exam with 3-4 questions

• Resources: Open notes; recommended to prepare a concise "cheat sheet" that captures key concepts, formulas, and definitions.

General Topics

1. Interaction between Transportation and Land Use:

   • Explore how transportation systems influence land use patterns and vice versa. Consider urban sprawl, transit-oriented development, and zoning laws.

2. Data Interpretation and Demand Models:

   • Understand the various data sources used for transportation studies, including surveys, traffic counts, and census data.

   • Familiarize with models like the Four-Step Model for estimating travel demand.

3. Transportation Equity and Analysis:

   • Analyze how transportation policies affect different demographic groups, particularly marginalized communities, and the importance of equitable access to transportation.

Transportation and Land Use Interaction

Travel Demand

• Derived Demand: Travel demand is characterized as derived, meaning it is a function of the ultimate need to reach destinations. Movement incurs various costs (time, financial, environmental).

• Factors Influencing Demand:

  • Demographic Characteristics: Reflect the needs, preferences, and lifestyles of travelers, including age, gender, and race.

  • Operational Quality: Various factors such as travel time, costs of transport, scheduling conflicts, and accessibility of different transportation modes impact individuals' decisions to travel.

  • Environmental Factors: Conditions like weather, topography, noise levels, and distance can significantly affect travel behavior.

  • Activity Types: Different activities, such as commuting for work, leisure outings, shopping, or academic purposes, dictate different travel patterns.

Travel Patterns by Demographic

• Gender: Constraints such as childcare responsibilities lead to shorter trips and increased chaining of errands for women.

• Age: As individuals age, mobility tends to decrease, with many elderly relying increasingly on public transportation systems.

• Ethnicity: Certain ethnic communities may exhibit high trip densities localized within the neighborhood due to cultural and social factors.

• Income: Lower-income groups often rely heavily on public transit, resulting in fewer trips and shorter travel distances, but car usage remains common for many trips.

Transportation Themes: Accessibility vs. Mobility

• Accessibility: Refers to the ease of reaching destinations, which enhances chances of participation in economic and social activities. Measures may include the distance to key services or employment opportunities.

• Mobility: Denotes the actual physical ability to move from one location to another, impacted by the available transport options and infrastructure quality.

Historical Context of Transportation and Land Use

Four Eras of Intra-Metropolitan Growth:

1. Walking and Horse + Buggy (Before 1890):

   • Characterized by limited distances and localized travel patterns where communities were built around walkable distances.

2. Electric Streetcars (1890 – 1920):

   • Increased accessibility to suburban areas and expansion of urban centers, allowing people to travel further from home for work or leisure.

3. Recreational Automobile (1920 – 1945):

   • The introduction of personal vehicles reshaped urban sprawl and suburban living, giving rise to highway systems and requiring more land for roads and parking.

4. Freeway Era (1945 – Present):

   • Infrastructure investments focusing on highway construction altered patterns of connectivity and land development, causing significant urban development patterns around freeways.

Analyzing Accessibility

• Accessibility Measurement: Determines the ease with which individuals can reach opportunities. It encompasses both mobility and land use efficiency.

• Cumulative Opportunity (CO) Measure: Evaluates the total potential opportunities accessible from a location, typically expressed in terms of travel costs.

Key Formula: Cumulative Opportunity (CO)

• CO = Σ (O_i / Travel Cost_i)

  • Where:

    • O_i = number of opportunities available at location i (e.g., job openings, services)

    • Travel Cost_i = cost (time, money) to reach opportunity at location i

Example Calculation:

Let's assume a neighborhood with three job locations (A, B, and C) with the following available job openings and travel costs:

• Location A: 100 jobs, $10 travel cost

• Location B: 50 jobs, $5 travel cost

• Location C: 200 jobs, $20 travel cost

Calculation:

• CO_A = 100 / 10 = 10

• CO_B = 50 / 5 = 10

• CO_C = 200 / 20 = 10

Total CO:CO = 10 + 10 + 10 = 30This indicates the overall accessibility in terms of potential job opportunities relative to travel costs.

Utility in Transportation Decisions

• Utility Definition: Rooted in attributes such as time and cost, incorporating subjective and objective components.

• Behavioral Modeling Overview:

  • Logit Probability Equation: Models decision-making based on various alternatives provided before the individual. Factors affecting decisions must be taken into account, including preferences and demographic variations.

Key Formula: Logit Model

• P_j = exp(U_j) / Σ(exp(U_k))

  • Where:

    • P_j = probability of choosing alternative j

    • U_j = utility of alternative j

    • Σ(exp(U_k)) = sum of exponentials of utilities for all alternatives k

Example Application:

Suppose an individual is choosing between three transportation modes based on their perceived utility values:

• Car: U_car = 3

• Bus: U_bus = 2

• Bicycle: U_bike = 1.5

Calculation of Probabilities:

1. Calculate exponentials of utilities:

   • exp(U_car) = exp(3) ≈ 20.09

   • exp(U_bus) = exp(2) ≈ 7.39

   • exp(U_bike) = exp(1.5) ≈ 4.48

2. Sum of exponentials:

   • Total = 20.09 + 7.39 + 4.48 ≈ 31.96

3. Calculate probabilities:

   • P_car = 20.09 / 31.96 ≈ 0.628

   • P_bus = 7.39 / 31.96 ≈ 0.231

   • P_bike = 4.48 / 31.96 ≈ 0.140

Interpretation:The individual has a 62.8% chance of choosing the car, a 23.1% chance of choosing the bus, and a 14.0% chance of choosing the bicycle based on their perceived utilities.

Econometric Basics

• Highlights how the dependent variable relates to one or more independent variables.

• Regression Model: A tool to simplify complex relationships into comprehensible quantitative patterns that aid in the estimation of effect sizes and significance.

Key Formula: Simple Linear Regression Model

• Y = β_0 + β_1X + ε

  • Where:

    • Y = dependent variable (e.g., travel distance)

    • β_0 = y-intercept (constant term)

    • β_1 = coefficient for the independent variable X

    • X = independent variable (e.g., income)

    • ε = error term

Example Application:

Imagine you want to forecast the average travel distance based on income. Through regression analysis, you find:

• Y = 2.3 + 0.5X

  • Here, every increase of an income unit results in an average increase of 0.5 in travel distance.

Connecting Transportation Planning and Individual Decision Making

• Travel Demand Forecasts: These forecasts gauge transportation needs and potential impacts related to planned improvements in infrastructure or policy.

• Approaches Include: Travel demand models, performance measurement strategies, and data visualization to communicate findings effectively.

Federal Regulations on Transportation Equity

Key Legislative Points:

• Executive Order 12898: Ensures that federal agencies identify and address disproportionate impacts of their programs on minority populations.

• Civil Rights Act of 1964, Title VI: Explicitly prohibits discrimination in all federally funded programs, ensuring equal service provision across race and ethnicity.

• Executive Order 13985: Directs federal agencies to assess conditions for underserved communities and improve equity in federal programs.

Existing vs Proposed Analysis Process

• Sheds light on deficiencies in current transportation analysis frameworks that often overlook systemic inequities affecting transportation accessibility.

Equity Analysis Framework

Key Steps:

1. Identifying Transportation Priorities: Set clear definitions for what constitutes equity in a transportation context.

2. Assessing Impacts: Model the effects of transportation changes across varied demographics, ensuring diverse voices are included in the process.

3. Measuring Costs and Benefits: Detailed assessment of costs and benefits across different groups to determine fairness and accessibility outcomes.

4. Comparative Analysis: Evaluate impacts across demographics to measure equity of transportation changes.

5. Developing Evaluation Criteria: Establish thorough metrics to assess equity and inform decision-making processes regarding transportation changes.