I've been seeing these signs all over lately, and I couldn't figure out what they were:
I finally had a minute to look it up on-line and it turns out that the state is now requiring National Grid to clean off power trucks and earth-moving equipment at the end of each power line corridor before taking the show on the road to another area.
Supposedly, this will help to prevent the spread of damaging bugs and other hitchhiking critters from one section of the state to another.
I guess this makes more sense than what I had been picturing:
Sometimes it's more fun inside my head.