Pricing and Financial Incentives for Modal Shift from Private Cars to Sustainable Transport: A Systematic Review

Shifting travel from private cars to public transport, walking, cycling, and shared low-carbon modes is important for urban decarbonisation, but the comparative effectiveness of economic instruments remains uncertain. Following PRISMA 2020, this review examined English-language peer-reviewed studies published between 1 January 2015 and 30 June 2026. The original OpenAlex search was completed on 18 August 2026, and bibliographic metadata were checked through Crossref. The documented evidence set contained 102 studies. Evidence was classified by instrument family, policy function, outcome directness, study design, and design-specific quality appraisal. Charges most consistently reduced charged zone or destination car activity, but confirmed modal substitution depended on available alternatives. Fare reductions more consistently increased ridership than displaced car trips. Short-run fuel-price responses were generally modest, while selected e-bike trials and subsidies produced promising but setting-specific changes. Evidence on tradable credits and integrated packages remained largely stated or simulated. Effectiveness depended on price salience, access to viable alternatives, targeting, service quality, and intervention duration. Integrated push–pull design should therefore be treated as a testable policy implication rather than established evidence that packages outperform their components.