I travel a great deal and actually take two.

An S&W 642 is what I carry and have immediately accessible in the vehicle. The reason is for its quickness into action and strength in extreme close-quarter scenarios which are the types of encounters I'm most likely to be involved in as a civilian trying to mind his own business.

I also take a 9mm Glock. Primary use is bedside in hotels.

I don't see any realistic need to take a long gun.