There is no need to waste energy feeling negative about traffic, even the worst traffic in the nation. On the contrary, it can be a chance to feel better and happier, if you have the right meditative skill.
If you consider your attention like a kind of currency -- you only have so much, and what you choose to spend it on is what you will receive -- then you will begin to see that you have a choice. You have the power to guide your experience of life by choosing what you decide to focus on.
Zazen is traditionally practiced sitting on a zafu pillow or bench in cross-legged full lotus with erect posture of spine and zero slouching. Part of the traditional character of zen is that it can require mental and physical discipline.
"Why should I question myself?" You might wonder. The answer to that question is found in the question itself. The fact that one is able to question one's self indicates that there is more to awareness than incessant thought, as many assume.