Can I use an enduro helmet for road cycling?

Physically yes, but it's not ideal. The visor creates aerodynamic drag and can obstruct vision in the road riding position. The extended coverage traps more heat than necessary for road riding. If you occasionally ride road to access trails, the enduro helmet works fine. For regular road riding, a dedicated road helmet is lighter, cooler, and more aerodynamic. Some riders remove the visor from their enduro helmet for road sections, which improves the experience significantly.