The North Korean Songun (선군정치), or "Military First" policy, prioritizes the Korean People's Army (KPA) in affairs of the state and allocation of resources. This has a profound effect on how North Korea operates, which ultimately trickles down throughout the country.
With one of the largest standing armies in the world, you can find soldiers everywhere you go in North Korea. The KPA even runs its own factories and farms. While driving through Nampho, I saw this rather unexpected scene. While North Korea does use machinery in agriculture and transport, this was a pretty rare sight throughout my tours. I would think this is more common in the countryside, but eventually there are limits to how much of the country you can see.