A closure adds a detour to your walk. The sign points confidently down another path, but it does not know your pace, daylight margin or last bus. An alternative route needs its own timing decision.
Stop where the choice is still easy
Read the official notice and identify the route on your map before moving on. Check whether the detour is intended for your activity and direction. A vehicle diversion, a temporary work access and a walking alternative are not interchangeable.
Do not bypass a closure because the original path looks shorter. If the alternative is unclear or unsuitable, turning back may be the sensible option.
Recalculate more than the distance
Consider ascent, surface, navigation difficulty and the condition of the group. A kilometre on a steep rough path may take much longer than one on a firm track. Include rests and the remaining journey after the trail, such as reaching transport or collecting a vehicle.
Compare the revised plan with available daylight, weather and the equipment you actually have. Do not treat a head torch or a downloaded map as permission to extend every walk indefinitely.
Choose a new decision point
Agree where or when you will turn around if progress is slower than expected. Make that decision while everyone is calm, not after the destination has become a test of determination.
If someone is expecting your return, update them when you can do so safely and explain the revised route and check-in plan. Do not assume they will infer the change from an occasional location update.
During the detour, compare actual progress with the revised plan. If the route proves more demanding, reassess again. A decision made at the first sign is not a commitment to ignore new information.
Afterwards, note what the map or description did not make clear. The next trip can benefit from that observation. A good walking day is not defined by reaching the original endpoint; it is defined partly by recognising when a changed route requires a changed plan.