Interesting that the SI enabling the trial of zebra crossings without Belisha beacons says that a sign *may* be used. My interpretation of the instrument is that if the zebra lines on the road exist |=| then it is a valid zebra crossing in law, even without Belishas or a sign.
The regulations now read: “A driver of a vehicle approaching a zebra pedestrian crossing where traffic sign number RPC 001 (zebra pedestrian crossing) or traffic sign number RPC 001A (zebra pedestrian crossing without belisha beacons) is provided shall yield the right of way to any pedestrian who has commenced crossing the road at the crossing.“ Where RPC 001A *shall* include lines on the road and *may* include a sign, detailed in the first link above.