Plenty of things could slow or derail that train for many years. We could, for example, discover that getting the required accuracy outside of areas with speci

Plenty of things could slow or derail that train for many years. We could, for example, discover that getting the required accuracy outside of areas with specific characteristics is infeasibly hard to solve in general, let alone with the onboard computer. We could have one or two horrific accidents fuel legal crackdowns that forbid driving AIs for a generation or more.