The Road Traffic (Signs) Amendment Regulations 2012 specify that a zebra pedestrian crossing be marked at either end by beacons emitting flashes of yellow light at regular intervals.
The purpose of these flashing beacons is to give motorists advance warning that they are approaching a pedestrian crossing, particularly during hours of darkness. Motorists, having been thus alerted, reduce their speed accordingly, allowing the vulnerable road users to cross more safely than if the beacon had not been there.
My Department is currently reviewing the use of unilluminated zebra crossings in other jurisdictions and I will consider that work in the near future.