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.
David M. Levinson (Sun,) studied this question.