Real-time Information and Behavioural Nudges to Trigger Modal Shift: A Field-Scale Randomized Evaluation

Urban congestion in India’s Tier-2 cities is driven by a psychological preference for private motorized transport despite expanding transit infrastructure. This paper proposes a novel "Carbon Yield" nudge—integrating individual travel behavior with India’s 2026 Carbon Credit Trading Scheme (CCTS)—to bridge the gap between national climate policy and personal mobility. We design a field-scale randomized controlled trial (RCT) involving 12,000 commuters in Indore, Madhya Pradesh. The study evaluates the incremental impact of Real-Time Information (RTI) and behavioral nudges on modal shift. We specify a technical data schema for smartphone-based mode detection and a robust statistical plan using Intention-to-Treat (ITT) and Instrumental Variable (IV) estimators. Synthetic results project a 4.5% increase in transit share, yielding a Benefit-Cost Ratio of 4.33.