Background. Built-environment sustainable travel interventions like superblocks, traffic calming or bike lanes often encounter vocal resistance despite broad latent support. Urban planners have been surprised by the virulence of backlash to seemingly benign measures, as seen in conspiracy-driven debates around the 15-minute city (Marquet et al., 2025) or frequent bike lane conflicts across Europe (Wild et al., 2018). To understand these reactions, we test psychological drivers of policy acceptability in the context of Barcelona's recent street transformations
Methods. A population survey of Barcelona residents (N=2,000) measured four latent constructs: Fairness, Trust in the City Council, Transport Policy Values, and Climate Concern, alongside socioeconomic and political variables (ideology, education, home ownership, car use and need). Support for expanding superblocks served as the primary outcome. We estimated a structural equation model (FIML/MLMV), regressing support on the four constructs and covariates, and regressing each construct on the same covariates. Reliability was acceptable to high (α Fairness≈.80; Trust≈.84-.87; Policy Values≈.62; Climate≈.82)
Results. Trust and Fairness were the strongest attitudinal predictors of support for superblocks (β≈.34 and β≈.24), with Policy Values also contributing (β≈.22). The direct effect of generic Climate Concern was negligible once other attitudes were included. Higher car use did not directly reduce support but was linked to lower Trust and weaker Policy Values, indicating an indirect pathway to opposition. Sociodemographic effects were modest but coherent, such as ideology shaping Trust and Values.
Conclusions. Procedural and distributive fairness, together with institutional trust, are key to acceptance of urban street transformations. Messages relying only on abstract climate benefits may be insufficient unless coupled with references to fair process, equitable outcomes, and transparent governance. Designing processes that build trust can help reduce backlash and sustain progress toward people-centered streets.