Get written permission first. In most (but not all) private landowners actually own the land, while the electric company or gas company has a lease or easement to cross the property with the lines (be they overhead electric lines or surface/subsurface pipelines). Just because the right of way is open and has an interesting road on it doesn't mean it is open to you. People around here have been known to put barbed-wire in the road to puncture tires or string cables/fences across the ROW to keep unauthorized people out. Think about it, would YOU want someone 4-wheeling across YOUR property, leaving garbage and tearing things up? I don't like it, either, yet I still have to pick up the trash and fix the fences.

Stephen