This is a partial transcript of "The Big Story With John Gibson," July 21, 2005, that has been edited for clarity.

JOHN GIBSON, HOST: New York City stepped up security measures in response to the London attacks, increasing security checks at the city's tunnels and bridges, as well as patrols in the mass transit system. Mayor Michael Bloomberg (search) announced that police will begin random searches of bags carried by people entering the subways.

Here to talk about what can be done to protect mass transit systems from terrorism is William Millar, president of the American Public Transportation Association.

So, did it surprise you to read that Mayor Bloomberg said we're going to, in New York, anyway, start random searches in the subways?

WILLIAM MILLAR, PRESIDENT, AMERICAN PUBLIC TRANSPORTATION ASSOCIATION: It didn't surprise me. Transit systems across the country are doing everything they can to try to improve the security of the 32 million customers that use public transit every day. Random inspections are something that was done in Boston a year ago during the political convention there. It has been done in other countries as well.

So, it does not surprise me that that stuff has been taken Thursday...

(CROSSTALK)

GIBSON: Mr. Millar, I ride these subways every day. Every single person on the subways in New York City carries a black bag. What do random checks accomplish?

MILLAR: What random checks can accomplish is a couple of things.

First, if someone is going to be doing something of a terrorist nature on the system, they need to know that there's one more level that they're being watched on and they have a chance to get caught. Second, other riders on the system, the experience in Boston was that they felt safer knowing that there was police present and others who were doing the inspections.

So, it has a dual-fold purpose of actually improving the security and also making people feel more secure. Both are important.

(CROSSTALK)

GIBSON: Can you secure the subway systems?

MILLAR: You have to do security in the subway systems in a different way than we have chosen to do it in the airports. The public transit systems (search) in America are what are called an open system. There are literally tens of thousands of places to board busses, many hundreds of places to board subways and other forms of rail transit.

So, you can't hope to lock it down the way we have done with the airports. Instead, you take an approach of many lawyers of security, many different activities, training of employees to be more observant, communicating with customers, making sure our customers are more observant and that they report things that they see that are out of place or not right.

GIBSON: William Millar, I'm sorry. I don't mean to cut you off, but I got to leave it there. Mr. Millar, thanks a lot.

MILLAR: All right. Glad to be with you.

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