What happens next?

How to practice courtesy and kindness
Hold open doors for people.
It may seem small, but it doesn't take a lot of time or effort, and someone holding open a door with a smile can make someone's day. Helping or just being courteous to other people can make you feel good about yourself.
In traffic, just keep reminding yourself that the person who just cut you off was probably having a bad day. Let others in front of you when there is a back up.