Last time I was at Lo Wu they had a 'snake' type queue which was catered by three operating desks. If one desk got held up, at least the other two desks kept moving. At other times (other crossings, cannot remember which), each desk had one line. Pick the wrong line and you could be in for a long wait! How to know which is the right line - try to pick one with what seems like frequent travellers to China - on several occasions I have seen aged relatives in large family groups who have not pre-registered their fingerprints, and when they get to the front of the queue have no idea what they are doing. This can be a lengthy wait for those behind them.