Bucket truck

There's a bucket truck outside, and a worker is going up the utility poles. At first we thought they were changing the light bulb in the dark street light, but they have gone on to a second pole and they seem to be stringing a new wire. I wonder what it is for?

ETA, next day: Last night that streetlight was working again. Guess the problem must have been in the wiring instead of in the bulb.