It is a debugging tool, designed to quickly get you to a point in a session that would only be reached after a long time (e.g. a hour of two of normal running) and then ran at normal speed to detect problems, etc.
But, as Trevor has pointed out above, this is not without penalties such as missing track marks and triggers which are vital for the correct operation of session rules.
For this reason, the feature should only be used by creators testing their own routes.