The U.S. Transportation Security Administration has a broad mission: protect the nation's skies, railways, ports, subway systems and other transportation networks.

But ask travelers what the TSA does and you'll likely get a decisive answer: airport security screening. Anyone who's flown a commercial jet in the past five years has encountered TSA workers, who on a daily basis screen more than 2 million passengers at airports nationwide for weapons, explosives and other banned items.

Now the agency is implementing several new policies and procedures nationwide. In Denver, it recently started a new employee screening program, and it plans to bring bomb and behavioral detection specialists on board in coming months.

Bill Allen, the TSA's acting federal security director in Denver, spoke with Rocky Mountain News reporter Chris Walsh about the new procedures.

1 What security measures are in place regarding airport workers?

Every airport employee has had an extensive background check and a threat assessment. They also have to have badges to get around, and airports have their own screening process. With our new program we pick random locations to physically screen employees going from restricted to secure areas. It's another layer of security.

2 What is your response to critics who say every employee should be physically screened every day, just as passengers are?

There are 30,000 badged employees at this airport, and we screen 42,000 to 52,000 passengers every day.

It would take a lot more people and a substantial financial increase to physically screen all employees every day. We have several layers of security that accomplish most of that already.

3 With the new program, though, you're only physically screening a small number of those 30,000 workers, and there are dozens of access points throughout the airport. How is it effective?

It's the whole random aspect. They don't know where we're going to be or when we're going to be doing this at any given time. We have multiple teams of people working multiple shifts. There are multiple levels of security for employees, and this is one of them.

4 The TSA is testing new X-ray equipment in Phoenix that can peer through clothing to detect explosives, firearms and other banned items (passengers can choose to use it or the traditional screening). Will we see that technology at DIA?

We have volunteered for that program here, but we have not been accepted yet. In general, the TSA would like to be able to use some sort of alternative to a physical patdown.

5 When traveling for personal reasons, do you ever slip up and, say, accidentally pack a bottle of water in your check-in bag or forget to take off your watch when going through the metal detector?

Me? No. I know the process very well. But my daughter is a different story.