In the paper a budget detection and allocation proposal aimed at reducing the annual number of road fatalities by 40% in the Italian main road network is reported. Road safety measures are divided into two categories: measures for road infrastructure improvements and measures for the control and the repression of infractions. The cost, expressed as equivalent annual cost, and the effectiveness, expressed in terms of reduction of fatalities (1,1 million ECU per fatal injury) and of casualties (0,025 million ECU per casualty) have been evaluated and compared. The effects due to the interaction between several measures have been assessed too, in order to gain information to be used in the choice of different strategies aimed at improving road safety. The cost of all the road infrastructure improvements and all the measures for the control and the repression of infractions is about 3600 million ECU per year and the reduction of fatal injury is between 49 and 54% (the reduction of casualties is between 41 and 45%). Since several combinations of road infrastructure improvements and measures for the control and the repression of infractions assure the required reduction of fatalities of 40%, a benefit-cost analysis may be carried out to evaluate the optimal combination of road safety measures. The combination with the best benefit-cost ratio is characterised by a cost of 450 million ECU per year, divided into 275 million ECU per year for the road infrastructure improvements and 175 million ECU per year for the control and the repression of the infractions. In this way it could be possible to spend 0,82 million ECU for each life saved, with a ratio benefit-cost equal to 2.