The current study investigated the effect of alcohol on simulated driving and cognitive performance across multiple blood alcohol levels (0.00, 0.02, 0.05 & 0.08%). The main objective was examine if the effect of alcohol was dose and task dependent and whether there was a mismatch in the development of acute tolerance across subjective and objective measures. Thirty participants (male & female) completed a simulated drive that comprised a rural highway which was divided into low and high traffic segments. In the driving scenario, a range of measures including speed maintenance, sign detection and hazard reaction were collected. Participants also completed a computer administered continuous performance test, a subjective measure of intoxication and had their breath alcohol level recorded. The experiment included a pre-alcohol, intoxicated and two post alcohol recovery conditions in which the measures were repeated at the same time intervals. Results showed no significant impairments in accelerator or brake reaction time but there was a significant increase in the number of crashes which increased in a dose dependent manner. There were no significant impairments in the sign detection task but traffic density was found to impair driving performance particularly in the heavy traffic segments. A significant Group*Density*Road interaction was also found, where the 0.05% group had a higher maximum speed on Road 4 than on Road 3 in the heavy traffic (70km/h) zone. There were no significant findings for the development of acute tolerance.