Rare sighting of a Traffic Warden in the wild?

Av National Library of Ireland on The Commons
And was it 6 o’clock when Elinor Wiltshire took this photo of a tram (no. 15?) crossing the canal at Portobello in Dublin?

Date: 1940-1950 (in theory, but could be later)

NLI Ref.: WIL 75[2]