The main objective was to study the efficiency of airbag and seatbelt combination in a frontal collision between two passenger vehicles by the means of experimental crash tests. To do this, we conducted crash tests in a controlled environment and in the vehicles there were crash test dummies to simulate the human occupant. Two experimental crash tests were conducted at the velocity of 35 km/h, where 1 set of vehicles used passive safety systems and 1 set did not had these systems. The occupants of the vehicles were custom build crash test dummies that resemble an average male human and have close characteristics to the Hybrid III 50th percent male dummy. The dummy head acceleration was measured and the injury potential was calculated using the head injury criteria in both cases (with and without an airbag). We predict that by using passive safety systems, the injury potential to the occupants will be reduced and by measuring the head acceleration, we could calculate the head injury criteria (HIC) and estimate the probability of injury based on the HIC values.