According to an example on page 8 of the rule book, the yellow player has 5 APs and moves level with the blue marker, taking the leading position but forfeiting 1 AP. Why would he not go ahead of the blue marker ? Especially as the 3 VP space is one ahead. Are you not allowed to move further ahead?
He could move further ahead. However, the assumption is that he wants to be on the Red space to be able to activate that next. If he moved forward to the 3-VP space, that is allowed but the next time White cubes came up, he would only be able to activate Brown.