What kind of easement is specifically for commercial use, like utility lines?

The appropriate choice for an easement specifically established for commercial use, such as utility lines, is an easement in gross. This type of easement does not benefit a particular piece of land (as an appurtenant easement would), but instead serves a specific person or entity. It is often used for utilities, where the utility company must install and maintain infrastructure like power or water lines across another property.

In contrast, an appurtenant easement is tied to the ownership of a specific parcel of land and is not solely for commercial activity. The notion of an exclusive easement implies that the easement holder has sole rights to use the easement area, which doesn't apply to typical utility easements that allow access rights for maintenance by the utility company and other stakeholders. The term permanent easement generally refers to the duration of the easement rather than its purpose, and while many easements are indeed permanent, in this context, it does not specify the type of service or function that characterizes easement in gross.