Pavement. For variety, it could be asphalt, concrete sheets, cobblestones, Roman-style fitted blocks of stone, or a layer of gravel.
A work crew laying new pavement.
A work crew digging drainage ditches along the sides of the road
A work crew building a bridge over a small drainage tunnel
The foreman, back where the work crew started, taking a nap.
A couple of bandits well-hidden behind some bushes but arguing loudly if they should ambush the approaching work crew when they get up close.