I work in the highway design industry and I am not aware of any such rule, at least in Minnesota. I would also doubt highly that any road authority would allow such a rule because it would severely restrict activities and would probably make projects cost more in an era of limited funds.
Many places are going to these one lane road closures (or in interstate freeways, two directional traffic on one side of the center divide) because of the many complaints over long, out-of-the-way detours. I think the consensus of many transportation departments is that the inconvenience of the one lane is better than the inconvenience of a detour, especially if the detour route is owned by a different road authority (county or city instead of the state) and they may insist on being paid for the added wear on the detour road.
It is a lot easier and cheaper to design and construct projects without any traffic (i.e. full detours) but in deference to the public convenience, many projects are being designed to be constructed with adjacent traffic. Yes, I admit is a pain and I do not like it when I’m caught up in it as well, but imagine the alternatives. They might be worse.
Oh, regarding making allowances for emergency vehicles, this thought is with construction crews and supervisors on all projects. The attitude is that they will do whatever is necessary if the need arises. But you can’t let that possibility paralyze you into not doing any construction.