The international E-road network is a numbering system for roads in Europe developed by the United Nations Economic Commission for Europe (UNECE). The network is numbered from E1 up and its roads cross national borders.
European route E40 is the longest European route, more than 8,000 kilometres long, connecting Calais in France via Belgium, Germany, Poland, Ukraine, Russia, Kazakhstan, Uzbekistan, Turkmenistan, and Kyrgyzstan, with Ridder in Kazakhstan near the border with Russia and China.