Protection of the society from the negative consequences of the road traffic is a global challenge. The greatest challenges are related to emissions of harmful combustion products and road safety. One of the possible solutions of this challenge is purchasing and using a new, more environmentally friendly passenger car (cleaner and safer). As a more environmentally friendly passenger cars, we considered electric and autonomous passenger cars. Although these cars are more environmentally friendly, their negative feature is high purchase costs. This paper aims to create a model for determining the period of use when the decision to purchase a new, more environmentally friendly passenger car instead of a new, less environmentally friendly passenger car (petrol or diesel) would be beneficial. For that purpose, we analyzed costs, emission and road safety during life cycle. The developed model was applied on real data from Great Britain. Using the results of the model, stakeholders and customers of passenger cars would be able to reach better quality decisions related to purchasing the new passenger cars.