Is it safe to travel from Chengdu to Jiuzhaigou by bus in March?

We plan to travel from Chengdu to Jiuzhaigou by bus on 15 March 2017. I learn that Huanglong National Park will be closed. Would Jiuzhaigou National Park still be opened to tourists by then? I heard previously that travelling by land can be quite hazardous - are the buses and roads better now?