Flagman

At the approach to Southampton Terminus, double track branches off to the left, runs alongside the platforms and then cuts across Canute Road on an open crossing under the protection of a flagman.

"The Bands played the National Anthem and the Royal Standard was cracked by the Flagman and flown beside the clocktower at the top of the Horse Guards building."https://www.army.mod.uk/news/splendour-and-precision-from-the-british-army-for-the-japanese-state-visit/