Our team was discussing how transportation needs assessment should work in the context of long-range planning, where future networks, land use patterns, population growth, and job numbers are all explicitly uncertain. At short-term and local scales, needs assessment is relatively well defined. We know how to identify safety problems, access gaps, and service deficiencies in specific places today. The challenge arises when we try to carry the idea of “need” forward into regional planning under uncertainty.

That discussion raised a familiar question: should transportation needs be defined primarily from an expert perspective, based on technical analysis and long-term system understanding, or from lived experience, based on what individuals report about the difficulties they face in daily travel? And if the answer is some combination of the two, what does that actually look like in practice?

Even when we aim to center lived experience, measurement itself is often shaped by preconceptions. Survey research shows how sensitive responses are to framing, and transportation studies have documented how solution-oriented prompts shape reported behavior (Stopher and Greaves 2007). When surveys implicitly assume particular interventions, we risk measuring alignment with professional values rather than uncovering unmet need.

Transportation needs can instead be measured empirically by focusing on experienced constraints rather than stated preferences. A growing body of research does this by asking not what people want or what should be built, but what trips were needed and not made, what activities were foregone, and which barriers prevented travel — including time, cost, safety, reliability, or physical ability. Often described as suppressed or unmet travel, this work treats respondents as authoritative witnesses to their own experience without asking them to design systems (Palm et al. 2024; Hjorthol 2013; Luiu et al. 2017).

These measures allow us, first, to track over time whether transportation needs are actually being met as people experience them. When paired with the contextual information already collected in household travel surveys, they also allow us to examine which underlying conditions are associated with transportation security. Vehicle access, land use context, household resources, caregiving responsibilities, physical ability, and social connectedness become variables to be tested rather than assumptions to be asserted.

Even a small, stable set of experience-based questions, repeated over time and across geographies, could let us ask a simpler and more honest question: are we becoming better or worse at meeting basic transportation needs, and what conditions seem to matter most?