The system of ejes viales (singular: eje vial, lit. "road axis") in Mexico City is a large network of wide arterial roads with coordinated traffic signals. They are mainly directed in one-way with a single lane going in the opposite direction used exclusively by public transportation. The network was a project of Mexico City mayor Carlos Hank González and the first part of the network, after extensive construction and demolition of buildings and removal of trees, opened in 1979.[1] With the exception of the Eje Central, a south-to-north eje passing through the historic center of Mexico City, the ejes are numbered with cardinal directions, for example going north from the center: Eje 1 Norte, then Eje 2 Norte, and so forth. In addition to the Eje number and directional, the streets retain their individual names, with one eje thus consisting of multiple sequential individually named streets.