Incorporating distributional impacts (equity) into the CBA framework

CBA transport equity
Eilya Torshizian, Anthony Byett, Eugene Isack, Alina Fehling, Milad Maralani


Transportation decisions can have large and varied impacts on travellers and their communities. It’s important to measure these effects and consider their impact on various groups when planning projects.

Waka Kotahi uses a framework to decide which transport projects and programmes to pursue. The economic business case must contain a cost–benefit analysis (CBA). CBAs assess the economics of a proposal by valuing (monetising) the costs and benefits to all members of society. However, CBAs sum across a wide range of people and don’t calculate inequities between groups or individuals, or who ultimately benefits from the project.

Transport equity discussions focus on social justice. Equity impact analysis helps policymakers to make good decisions for a wide range of people. Distributional impact analysis needs to be complemented with wider investment and planning considerations. This includes any comprehensive policy framework that accounts for the overlapping effects of transport, housing and taxing policies.

Read the report here.

Cite this article

Torshizian, E., Byett, A., Isack, E., Fehling, A., & Maralani M. (2022). Incorporating distributional impacts in the cost–benefit appraisal framework (Waka Kotahi NZ Transport Agency research report 700).