My understanding of tier 4, as Mr Wong said in his evidence, is that it is only at tier 4 that the human is removed from the equation; I think that those were his exact words. I must admit that that seems to be a contradiction. Tier 5, as I understand it, is a fully automated vehicle with no steering wheel, totally under the control of technology. One wonders what tier 4 is. If tier 3 is the transition between human and vehicle and tier 5 is a fully automated vehicle with no steering wheel whatever, what is tier 4? Is it a lesser tier 5 or a greater tier 3? I will give way to the Minister, who is going to enlighten us.