I have my CCW (Carrying of Concealed Weapon) license. In Kentucky, you must go through an instructional class before getting your weapon -- and you learn that pulling your weapon out should only happen when you're prepared to use it in a lethal manner -- otherwise the aggressor could fight you for your weapon.

You don't get a handgun as a show of force -- you get one to protect yourself from imminent harm...and some asshat blocking a bus isn't putting you in imminent harm: you're in the bus, and hopefully the bus driver has already called 911 to get the person/people who are blocking the road out of your way.