An issue in driving simulation is that behaviour displayed in simulation does not exactly replicate behaviour in real-life. For example, roadside vegetation density impacts a driver’s speed and lateral position in on-road studies, but not in driving simulator studies. In this study it is investigated if the increase in fidelity and presence that head mounted display based virtual reality bring forth, yields behavioural adaptation as shown in real-life by evaluating the effect of three different roadside vegetation density conditions in a novel head mounted display based virtual reality driving simulator. Twenty-nine participants drove a 2m wide car over a 11km long 3.5m wide winding road. Participants completed three trials driving through three different roadside vegetation density conditions per trial, the density conditions being light (one tree per 40m), medium (one tree per 20m) and dense (one tree per 5m). The effect of the density conditions was evaluated with respect to speed, lateral position, steering reversals, subjective workload and self-reported risk. Increased vegetation density increased self-reported risk, but did not affect speed or lateral positioning. This finding is congruent with findings in con- ventional simulator studies, which could indicate that despite the advantages of head mounted display based virtual reality regarding fidelity and presence the resulting driving behaviour still has a closer connection to conventional simulated driving than real-life driving. In future work the built and implemented simulator can be improved and optimized, furthermore the relative validity of the simulator should be investigated.