The TSA says that more than 25 million fliers have used the zip-through-security program since its soft rollout in 2011.

Now it is opening a registration Web site, sign-up centers at major airports and a few downtown locations nationwide, with the first at Indianapolis International Airport this week and one set to open at Dulles International before year’s end.

Opening the enrollment centers, 300 in all, will be a step toward TSA Administrator John S. Pistole’s grander plan to reduce the security hassle for low-risk passengers so his workers can focus on those who give some reason for suspicion.

“TSA Pre-Check is enabling us to move away from a one-size-fits-all approach to transportation security,” Pistole said.