Temporary signs
Temporary signs manage a situation that will not last: road works, a diversion, a damaged carriageway, a landslide, or a controlled section where traffic alternates.
They may be handheld - a STOP/GO board at a works site - or placed on the road with cones and barriers. While they are in force they carry the same authority as permanent signs, and they replace whatever the permanent signs said.
Expect a lower speed limit, people working close to live traffic, and loose surface material. Slow down and follow the flagger's instruction even where it contradicts the road markings.