Yes, it's normal. It's referred to as Z-fighting. It's your GPU / drivers having trouble identifying which textures should be loaded first, frame by frame. It's caused by viewing certain meshes and textures at a certain distance from a certain angle. You'll see it in lots of games.
Sometimes, tweaking draw distance settings can mitigate it, but it's almost impossible to eliminate completely. It all depends on what's loaded in for a given scene and how the drivers interpret the data.
(In this case, it looks like two 3D models may be slightly overlapping, causing the z-buffer to constantly swap which one is nearer to the camera.)