Wikipedia says that the Trailblazer trains with individually ratcheting lapbars were introduced in 2003. I'm in favor of this for anything that little kids are going to ride on. The single-position lapbars on the Dragon Coaster at Canobie make me kind of nervous; the mitigating detail there is that the Dragon only curves to the right, so you can put the kid on the inside to make it less likely she'll fall out.