If one lamp is not working, then the lamp itself is probably broken. If the whole street is affected, then it will be a problem with the street lighting cable or a short circuit.
Compare it with your situation at home:
sometimes just one bulb is broken (easy to replace)
sometimes all the electricity in your house or in a particular room goes off: in that case, you have to look for the cause of the short circuit to repair the fault (can be complicated).
