Generally I see
indicating an emergency exit on a bus, whereas I see
indicating an emergency exit in a building. I'm not clear on the difference between them.
Question: What's the difference between 应急出口 and 安全出口 which both mean "emergency exit"?
Looking at dict.cn:
This makes me suspect that an 应急出口 can only be used in the case of an emergency, whereas an 安全出口 can be used at other times too. But I may be reading too much into this.