Urban traffic problems are a key challenge in modern cities internationally; in terms of traffic congestion, road safety, and environment. The need for sustainable transport policies is increasingly recognized and receives more and more attention. The objective of the present paper is to investigate the socioeconomic impact of the implementation of an environmental transport charging policy on road safety in terms of fatalities and injuries within a 15 years horizon. Specifically, an environmental transport charging policy called Green Car Access Card (GCAC) is examined for the daily access of a passenger car in the center of Athens, Greece with the charging being adjusted according to the Euro class of the car. To achieve that objective, a stated preference survey has been conducted leading to the development of a mixed binary logistic regression model to estimate the public acceptance of the examined environmental charging policy. For the road safety assessment, the number of road fatalities and injuries in the “Do nothing” Scenario and in the “GCAC” Scenario as well as the human cost per fatality and injury are taken into account. For the road safety estimation in the next 15 years, the technological renewal of passenger cars as well as the change of the average speed in the centre of Athens are considered. During the first two years of the GCAC policy operation a significant higher road safety cost is estimated in the “GCAC” Scenario compared to the “Do nothing” Scenario but in the following years of operation the road safety benefit in terms of fatalities and injuries as well as in monetary units increases in relation to the “Do nothing” Scenario. In a time horizon of 15 years is estimated an overall road safety economic benefit 74,647,722 €.