HotLine, it’s fairly common to provide overcurrent protection for street lighting in the form of a submersible fuseholder with a UL class-CC fuse. They can be hidden in subsurface concrete boxes or in pole bases at the handhole. In more recent underground-fed poles, typically municipalities specify an equipment-ground conductor routed with the circuit conductors. A ground rod or a ‘Ufer-like’ flat coil of ~6AWG solid copper at the concrete-form base is often called out, but as supplemental ground electrode for lightning protection. Think about it—metal light standards make superb “air terminals” (lightning rods.) An example of a submersible fuseholder is the Bussmann HEB-series part.
http://www.bussmann.com/library/bifs/2127.PDF Littlefuse and Shawmut sell ‘em too.
For overhead duplex spans to metal poles, it’s possible to treat the situation as it if was a junior unmetered 2-wire service entrance, and bond the grounded-circuit conductor to the electrode and pole metal. Agreed that there may be older installations where a street-full of metal poles is served by a pair of unfused overhead ungrounded conductors, where a ground fault in a pole would not clear an overcurrent device. An old school of thought may have been that no overcurrent protection meant fewer outages, but discharge-lighting ballasts can blaze nicely if there’s no upstream overcurrent protection.
Properly sized streetlighting fuses have another feature—if a ballast craps out and its local fuse opens, the rest of the circuit still runs.
