I’ve seen a tutorial for fixing that in a tile map, or a landscape where grid lines appear that are not enabled. The fix was changing the skylight from stationary to movable. So, if the scene is using a movable skylight, try changing to stationary and back to movable. Same for the directional light, if the skylight isn’t enough or doesn’t work.
Another possible fix is locating the tile/mesh a little offset from the adjacent tile/mesh along the axis the road is set. So, if the road is running along Y-axis, change its Y location value by 0.01 away from the previous road mesh/tile. For some unknown reason, when meshes are lined up at their faces, flickering occurs. It’s sometimes called z-fighting, so it might help to research that term for information on why/how it occurs.