Seeking causality in transport research

Recently published

• Levinson, David (2026) Seeking causality in transport research. Transportation Research Today. Volume 1, Issue 1, Article 100001. [doi]

Abstract

Transport policy asks causal questions, yet much transport research answers them with associative designs and then uses causal language. This Perspective (i) distinguishes causal, associational, and descriptive claims, (ii) offers a compact set of norms and a checklist for aligning claims with identification, and (iii) illustrates these ideas with examples drawn from pricing, operations, access, network evolution, and evaluation.

Keywords

Causality, Inference, Perspective

Fig. 1. Example causal diagram for a congestion charge, illustrating how confounding (for example, demand) and simultaneous changes (for example, fuel prices, transit service) can bias naive before–after comparisons. Colors and symbols indicate hypothesised directions.