I think what's going on is that real world driving requires deviations from a strict reading of the law from time to time. People take advantage of that fact to deviate from the law even when it's not advantageous to safe driving. People in the Northeast are more likely to interpret the law flexibly, which in some cases produces better driving and in other cases produces maniacs. In the Northwest, people are more civil and by-the-book, and may very well know the letter of the law better, but that causes its own problems.