Work to erect or lay telegraph or telephone wires, to construct street or interurban railroads, to lay gas pipes for the purpose of carrying gas for light, heat, or power, to erect poles or wires for transmitting electricity for light, heat, or power, along or upon any public street or highway, or to exercise any other privilege whatever, a franchise for which has been granted pursuant to this article, shall be commenced in good faith within not more than four months from the granting of the franchise. If not so commenced the franchise shall be declared forfeited.
Ca. Pub. Util. Code § 6013