The aim of this project was to investigate the behavioural validity of virtual methods, namely driving simulators and computational models, as prototype HMI evaluation tools. A driving study was designed where participants had to perform secondary tasks while driving in a real world and a driving simulator setting. Statistical analysis of the data, along with an in-depth review of related findings was used to identify the levels of behavioural validity that could be achieved by different simulator settings across different metrics. A further analysis was performed to identify behavioural strategies that drivers employ regarding their visual attention sharing while executing HMI tasks concurrently to driving. Finally, two existing computational models were validated and a novel model was proposed that can account for drivers’ behavioural phenomena, not previously accounted for.