Road expansion refers to the increasing rate at which roads are constructed globally. Increases in population size and GDP, particularly in developing nations, are the primary drivers of road expansionMeijer, J. R.; Huijbregts, M. A. J.; Schotten, C. G. J. & Schipper, A. M. (2018). "Global patterns of current and future road infrastructure". Environmental Research Letters. 13 (6), 064006. but transportation planning decisions also play an important role. The anticipated length of newly paved roads to be built between 2010 and 2050 would encircle the planet more than 600 times.Laurance, W.F., Clements, G.R., Sloan, S., O'Connell, C.S., Mueller, N.D., Goosem, M., Venter, O., Edwards, D.P., Phalan, B., Balmford, A., et al. (2014). A global strategy for road building. Nature 513, 229–232 Approximately 90% of the new roads are being built in developing nations.Dulac, J. (2013). Global land transport infrastructure requirements: Estimating road and railway infrastructure capacity and costs to 2050 (Paris, France: International Energy Agency), p. 50. Africa and Southeast Asia are predicted to experience a large amount of road expansion shortly.
Road expansion in Asian countries is a significant aspect of infrastructure development, driven by urbanization, economic growth, and connectivity needs. Countries like China, India, and Indonesia have ambitious plan for expanding their road networks to accommodate increasing traffic and trade demands. These projects often face challenges related to land acquisition, environmental impact, and funding, but they play a crucial role in fostering economic development and improving accessibility for remote regions.
Roads facilitate access to markets, health services and education but may adversely affect the natural environment, and impact communities and economies. There is also a disagreement on whether expanding and widening congested roadways truly relieves traffic congestion.
Effects on the Environment
The expansion of road infrastructure can have numerous impacts on environmental systems. Road construction and usage can serve as a significant source of mortality for wildlife.Laurance, W.F., Goosem, M., Laurance, S.G.W., 2009. Impacts of roads and linear clearings on tropical forests. Trends in Ecology & Evolution 24, 659–669.Trombulak, S.C., Frissell, C.A., 2000. Review of ecological effects of roads on terrestrial and aquatic communities. Conservation Biology 14, 18–30. Roads can affect animal movements either by acting as a barrier or allowing easier movement.Forman, R.T.T., and Alexander, L.E. (1998). Roads and their major ecological effects. Annual Review of Ecology and Systematics 29, 207–231.Laurance, W.F., Croes, B.M., Tchignoumba, L., Lahm, S.A., Alonso, A., Lee, M.E., Campbell, P., Ondzeano, C., 2006a. Impacts of roads and hunting on Central African rainforest mammals. Conservation Biology 20, 1251–1261.Blake, S., Deem, S.L., Strindberg, S., Maisels, F., Momont, L., Isia, I.-B., Douglas-Hamilton, I., Karesh, W.B., Kock, M.D., 2008. Roadless wilderness area determines forest elephant movements in the Congo Basin. PLoS ONE 3, e3546.