A public road easement is a right of way recognized under Florida law which includes the right to enter for certain purposes, which limits a property owner's otherwise exclusive right to his property. If a road easement exists, that means that at some point the county or an adjacent property owner could put in a road. It does not make that land public property: Bill still owns the land. Bob is trespassing on Bill's land, and can call the police to have Bob ejected. The situation is not substantially changed if there is also a power line easement, though of course if he is trespassing next to power lines there is some additional urgency to ejecting the trespasser. It is reasonable to suspect an intent to violate Fla. Stat. 812.14 "Trespass and larceny with relation to utility fixtures".
It would be a violation of 810.09 to enter and remain if
notice against entering has been given, or
the property is the unenclosed curtilage of a dwelling and the offender has the intent to commit an offense (e.g. 812.14). Bill or his agents can order Bob to leave, and if he does not comply, he has committed a crime. However, the police are not empowered to serve such notice on Bob, in case Bill is a regular old landowner. That opinion only applies to private landowners, so if the landowner is a government agency, they could well be enabled to serve the requisite notice to leave.