As someone who travels the country for my job, I can say that Texas has the worst drivers in the country, Houston and Dallas drivers are dangerous.  I have worked in Denver and can tell you they do not have the worst drivers.  If you want to see the worst drivers in the country, look for the people coming over from India, I almost got rear ended because I came to a full stop at a stop sign.  My neighborhood has a big influx of Indian people and they drive like they do in their country.