A separate paid, card-linked, or status-based lane before the X-ray belt, at airports large enough to run one. This covers the airport's or an airline's own fast-track service — not US TSA PreCheck or CLEAR (see Trusted Traveler Programs), and not what happens once you're through the checkpoint (see Lounges). Only airports with a genuine, officially documented service are listed — a handful of well-marketed "fast track" names turned out to be private concierge resellers with no actual separate lane, and those are left off. Few of these programs publish an exact time saved; expect a shorter line, not a guaranteed number.
Fast-track and priority-security programs change price and eligibility without much notice. Confirm current terms on the airport's or airline's own site before relying on one to make a tight connection.