What situation may necessitate a detour?

A complete road closure for major construction work clearly necessitates a detour because it prevents all traffic from passing through that section of the roadway. When a road is entirely closed, vehicles cannot navigate through, creating a need for an alternative route to ensure continued flow of traffic and maintain safety for both drivers and construction workers.

In such scenarios, appropriate detour signage and guidance are critical to redirect vehicles onto safer, operative routes. This minimizes congestion and confusion, while also allowing construction activities to be completed efficiently and safely.

The other situations, such as minor road repairs, temporary lane shifts, or scheduled traffic signal updates, typically do not require a full detour since they may allow some level of traffic to flow or can be managed with reduced access instead of complete closure.