Use trail running gear instead of road running gear when the surface, route, and conditions create problems that road gear is not built to solve. Loose dirt, mud, rocks, roots, elevation changes, remote routes, and fast weather shifts all change the equipment job.
Trail gear is not automatically better. It can be heavier, warmer, stiffer, or unnecessary on pavement. The useful decision is whether the route needs traction, protection, carry capacity, navigation, or weather margin beyond a normal road run.