Yes, back when I was an apprentice. We attached conduit to the bottom of a covered bridge at a winery.

You (or your contractor) will be responsible for installation of the primary conduit run in whatever path it takes. But your utility (GMP or others) will design that installation for you. Primary (before the final transformer) is outside the jurisdiction of the NEC and local inspectors if applicable. The utility will specify what conduit(s), cover, attachments, etc… for you depending on the particulars of your project.