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 mostly one-way with one lane going in the opposite direction for the exclusive use of public transportation. The network was set up during the presidency of José López Portillo in the 1970s. 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.