I call it dumb luck and being too cool-headed most days. I never have an issue in the country, but as soon as I get into the city it seems like the rules of the road just evaporate. 75% of my bad driving clips occur in the city, which accounts for only 10% of my commute. Defensive driving is the name of the game.
I tried being cheap and just using Movie Maker, but it's a flawed program. I finally bit the bullet and used Sony's generous student discount to buy Vegas Movie Studio (a slightly dumbed-down version of Vegas Pro).
It's not the most feature-packed video editor for the retail price, but I'm well acquainted with the Vegas UI and it was 62% off, so Movie Studio was the obvious choice for me.
Here's my channel, not too much to it, just random driving videos.
https://www.youtube.com/channel/UCwYsUcbZPMxfK6LGxCdrCDQ