Detour

A detour or (British English: diversion) is a (normally temporary) route taking traffic around an area of prohibited or reduced access, such as a construction site.

[citation needed] Depending on the roadway affected, and the scope of construction, different types of detours may be used.

The most basic is to simply close a stretch of roadway for a defined period of time, diverting all traffic around the site.

Which type of detour to use is decided by a variety of factors – a full closure of a road means construction can be completed more quickly, but also means a more severe impact on traffic.

[2] Detours require signage to notify drivers, especially those who are not local and are unfamiliar with the road network in an area.

A partial detour in the United States, with the road restricted to local traffic only.
Detour sign used in Singapore
Detour sign used in Italy
Extreme weather events such as heavy snow require temporary detours to be used until roads and railroads can be cleared and reopened.
Diverted cycle route in the UK
Detour sign used in the United States