At least its better than having a 4mm street lighting cable feed fused at 500 amps, which would have been the case if the street lights were fed directly of the street main.
In the case of the street main feeder system, a fault with the street lighting cable tends to knock out an entire street at one go, as the street lighting cable (effectively fused at 500 amps) burns back to the main, flashes over at the main, and causes a blackout.