In recent decades, economic renewable energy technologies have been developed for the electricity and heat sectors. Although there has been some development in the transport sector, there is still no well-establish sustainable alternatives to oil. In this study, a new alternative is proposed to convert road transport from oil to electricity. This involves the electrification of major roads so that electric cars, vans, busses, and trucks can use electricity as their primary fuel over long distance, which in this study is referred to as ‘RoadRail’. This is a new and radical alternative for the transport sector in the future, so no specific technological design is promoted here. Instead, the aim in this study is to carry out a socio-economic feasibility study of the RoadRail infrastructure by using indicative costs relating to similar technologies. Using assumptions for vehicle costs and electricity/oil costs, Denmark is presented as a case study for the installation of RoadRail. The results indicate that based on 2020 cost assumptions, RoadRail is a more socio-economic alternative than a business-as-usual using oil. This is primarily due to decreasing electric vehicle costs, decreasing electricity production costs, and increasing oil prices. Furthermore, the additional costs of the RoadRail infrastructure is less than 5% of the total transport costs in all scenarios considered here. This indicates that if the RoadRail infrastructure can be developed for similar costs to those assumed here, then the technology offers an economically viable alternative to oil for road transport while also using the most sustainable form of fuel in the future, electricity.