US v Europe Low Vis Ops.
In the US, pilots can assume they have cat 3 protection as soon as the weather drops below limits unless ATC tells them otherwise.
In Europe, pilots don’t have cat 3 protection until they are told LVPs in place.
One is fail safe, one is fail dangerous.
As someone said earlier, a sudden drop in vis during a busy period of departures or with runway works or free ranging vehicles could mean there is a delay in activating LVPs, surely it’s more safe to assume runway is not protected until specifically notified?
And from a human factors point of view, moving into a different method of operation - a different mental mode by announcing Low Vis Procedures on ATIS and frequency and confirming with pilots, wouldn’t that make it less likely the controller would make a mental slip and try and get a departure away in a non LVP gap?