|Ph.D Student||Nahmias-Biran Bat-Hen|
|Subject||Incorporating Equity Considerations in Transport Project|
Evaluation: Developing New Measures
|Department||Department of Civil and Environmental Engineering||Supervisor||Professor Yoram Shiftan|
|Full Thesis text|
In this work, we develop an innovative and comprehensive transport evaluation criteria accounting for distributional effects and accessibility. In order to assess the full benefits of transportation projects on various consumers and estimate the improvement in accessibility, it is best to use Activity-Based Modes (ABM). ABM has two important implications for equity analysis, which have not been utilized in the literature so far: first, its ability to analyze results by various groups of the population; second, its ability to use the Activity Based Accessibility (ABA) measure to estimate the overall benefits from transport investments and policies. The ABA measure allows one person to have different accessibilities for different choice situations, depending on his/her characteristics.
Transport project appraisal is usually done using Cost Benefit Analysis (CBA). However, this method is limited in its ability to deal with equity issues. Furthermore, it has a built-in distributive mechanism that is biased, and it thus structurally favors transport improvements for highly mobile groups. We suggest two alternative frameworks that can take into account both efficiency and equity considerations:
1) We use Subjective Well-being (SWB) measure combined with the ABM accessibility measure (ABA). The ABA expresses the consumer benefits as it captures the overall utility from all the travel alternatives over the various dimensions. The SWB measure reflects the magnitude of the income - well-being effect on different population groups; it expresses the fact that the change in well-being is more sensitive to changes in income for lower income consumers. By translating the consumer surplus into the consumer subjective well - being we can overcome income differences and also establish transport economic evaluation on both objective and subjective measures. Considering the change in accessibility calculated at the top of the hierarchy, including the income - well-being effect, we get an alternative measure, "Subjective Value of Accessibility gains" (SVOA), as the key benefit taken into account in Equity Benefit Analysis (EBA).
2) We apply the Capability Approach (CA), which is derived from the actual opportunities that people have, given their personal and social circumstances, to transportation. we use ABM accessibility measure to reflect person's abilities to reach essential activities, by calculating it only for selected destinations, which contributes to travelers’ capabilities. These are destinations within travelers’ realistic range of use; and then the consumer surplus becomes the consumer capability. Considering the change in accessibility calculated at the top of the hierarchy, in monetary terms including only destinations that enhance travelers’ capabilities, we get an alternative measure, "Value of Capability gains" (VOC), as the key benefit taken into account in CBA.
The proposed new frameworks are demonstrated through synthetic case studies as well as a full scale, real world case study using the San Francisco Bay Area Metropolitan Transportation Commission’s activity-based travel model for different scenarios. Results indicate that the SVOA and the VOC can show higher benefits to policies focusing on the needs and capabilities of more vulnerable social groups by providing them a greater benefit compared to the result obtained using the traditional measure.