Climate change is an inevitable and urgent global challenge with long-term implications for the sustainable development of all countries. In order to respond to climate change, it is very important to identify new ways of reducing greenhouse gas emissions. The present paper emphasizes that the use of a greener and more efficient means of transport, such as a highway (in this case Buzău-Focșani) is more beneficial in terms of reducing greenhouse gas emissions than using old infrastructure. Through specific traffic data processing and dispersion modelling, it was shown that the polluting emissions will increase in the next years, in case of using the already existing road, while the use of a sustainable highway provides a downward trend for these emissions. The construction of the highway will have positive effects on air quality, will ensure a good traffic flow, but the benefits will be even greater when the replacing of the existing car fleet (Diesel vehicles) with hybrid and electric vehicles will take place.