What does this sign mean?

这个标识代表什么意思？

阅读相关知识

It remains compulsory even without workers present. Follow the limit until an applicable end or change sign.

临时限速同样必须遵守，不能因为施工人员暂时不在场就忽略。应按配套限速数字及后续结束、变更标志行驶。