More than 1 million people have enrolled in the US expedited airline passenger screening program, TSA Pre-Check.

The Transportation Security Administration (TSA) launched Pre-Check in October 2011. In December 2013 the agency opened its first application center at Indianapolis International Airport, allowing people to apply for Pre-Check directly. There are now more than 330 application centers nationwide, including locations at 31 airports.

Pre-Check has been lauded as a significant step in TSA’s efforts to transform air traveler screening to a more risk-based system that permits people, once approved, to wear shoes, light jackets and belts as well as keep laptops and gel bags in their carry-on luggage as they go through designated security lanes.

Much credit for Pre-Check and TSA’s intelligence-driven, risk-based processes is given to former Administrator John Pistole, who retired from TSA at the end of 2014. Pistole is this year’s recipient of the ATW Excellence in Leadership Award.

“The continued growth and passenger participation in TSA Pre-Check affirms our commitment to the evolution of our intelligence-driven, risk-based approach to aviation security,” TSA Acting Administrator Melvin Carraway said.

Approved travelers receive a “known traveler number” which allows them to use the designated Pre-Check lanes. Eleven airlines are now participating in the program—Air Canada, Alaska Airlines, American Airlines, Delta Air Lines, Hawaiian Airlines, JetBlue Airways, Southwest Airlines, Sun Country Airlines, United Airlines, US Airways and Virgin America.