China hosts surprise visit by Kim Jong Un amid US tensions
https://edition-m.cnn.com/2019/01/07/china/kim-jong-un-visit-china-intl/index.html?r=https%3A%2F%2Fedition.cnn.com%2F
The reason why Kim family avoid using train is rumored to be horror of being shot down or crashing.
But, considering that something exploded in Ryongcheon station just after train carrying Kim Jong il passed through the station, and that similar accidents have happened in the nation once in several years, it's difficult to say rail transportation in North Korea is safer than airplane.
