The rapid growth of app-based mobility services has transformed urban transportation in Indian cities, with bike taxi services emerging as a popular and affordable commuting option. This study examines the factors influencing the adoption of bike taxi services among commuters in Tiruchirappalli city by integrating the Technology Acceptance Model (TAM), Theory of Planned Behaviour (TPB), and travel behaviour factors into a unified conceptual framework. Primary data were collected from 304 commuters through a structured questionnaire and analysed using simple percentage analysis, reliability analysis, correlation analysis, regression analysis, independent sample t-test, and one-way ANOVA. The results indicate that perceived usefulness, perceived ease of use, attitude, subjective norms, perceived behavioural control, travel cost, travel time, convenience, safety perception, and availability all significantly influence user adoption. Demographic variables including age, gender, monthly income, and occupation did not show any significant difference in adoption behaviour, suggesting that bike taxi services are widely accepted across all population groups. The study provides meaningful insights for service providers and policymakers in developing strategies to promote sustainable urban mobility and supports SDG 11 — Sustainable Cities and Communities.