The expansion of road networks, taken place during the last decades, was driven by technological progress and economic growth. The most innovative products of this trend—modern motorways and international road corridors—provide an excellent level of service, traffic safety and necessary information to travelers. However, despite this undeniable progress, major impediments and respective challenges to road authorities and operators still remain. The present paper analytically presents the main current challenges in the road engineering field, namely: a) financing new projects, b) alternative energy resources, especially renewable energy, c) serviceability, including maintenance of road infrastructure, traffic congestion and quality of the network, d) climate change hazards due to greenhouse gas emissions increase, e) environmental impacts, f) safety on roads, streets and motorways, and g) economy and cost-effectiveness. In each country and over each network, challenges and concerns may vary, but, in most cases, competent authorities, engaged in road development policies, have to deal with most of these issues. The optimization of the means to achieve the best results seems to be an enduring stake. In the present paper, the origin and the main features of these challenges are outlined as well as their tendency to get amplified or diminished under the actual evolving economic conditions worldwide, where growth alternates with crisis and social hardship. Moreover, responses, meant to provide solutions to the said challenges, are suggested, including research findings of Aristotle University and innovative technological achievements, to drive the transition to a more sustainable future.

Infrastructure development is critical for sustaining Asia’s economic growth. Unfortunately, huge financing gaps—estimated by a recent Asian Development Bank study to be USD22.5 trillion—constrain the ability of most emerging Asian countries to fully realize the benefits of infrastructure development. For instance, over 70% of infrastructure investments in Asia are still funded by public resources, which pose acute financing challenges for many countries with limited budgets and fiscal constraints. This paper discusses some of the challenges associated with public financing of infrastructure projects in emerging Asian countries, before introducing some new options for alleviating their infrastructure investment needs. In particular, it proposes a new approach to infrastructure financing by utilizing the spillover effects of infrastructure investment, where additional revenues generated from such investment can be channeled back to investors as subsidy to increase the returns to their investment. The paper also argues the need for Asian countries to implement fiscal reforms and to develop a more balanced approach to financing, one that involves both the private and public sector.