Brief Detail: This dissertation developed a Complete LAne-Changing Decision (CLACD) modelling framework that explains both the mandatory and discretionary lane-changing behaviours, incorporates both the successful and failed lane-changing attempts, and describes lane-changing behaviours in both the traditional and connected environments. To test different components of CLACD, high-quality vehicle trajectory data were collected using the CARRS-Q advanced driving simulator. The models developed in CLACD were compared with competing models from the literature and results demonstrated the superiority of CLACD.