Transport is a key economic sector, supporting economic development and growth, and facilitating exchange. At the same time, motor vehicles are major emitters of gaseous and particulate pollution in urban areas. The transport industry's quest to limit its impact on the environment and improve road safety continues to drive policy, research and development. Eco-driving is a well-established, affordable and simple behavioural change intervention, which could reduce fuel consumption up to 20%. Fully electric vehicles are predicted to be available for the mass market by 2020, however an energy efficient driving style will still be necessary for these vehicles due to a relatively poor battery performance. Furthermore Eco-driving could be applied to electric or thermal vehicles. Despite a widespread adoption of Eco-driving, its safety benefits have not been clearly established. This paper discusses research issues related to Eco-driving interventions. It covers policy, industry practice and research approaches ranging from education to in-vehicle technology. This paper demonstrates the lack of comprehensive systemic research analyzing the impacts of Eco-driving on road safety. Most of the methods used to assess the benefits of eco-driving lack scientific rigour and have methodological shortcomings. Ecological Driving Assistance Systems (EDAS) has emerged as a viable ITS intervention addressing Eco-driving but the associated Human Machine Interface is still neglected. Furthermore, there is not enough research assessing the long-term effects of Eco-driving driving.