A story in the Baltimore Sun (https://articles.baltimoresun.com/2011-05-26/news/bs-md-maryland-drivers-20110526_1_maryland-motorists-gmac-insurance-drivers) notes that Maryland drivers were rated 3rd from the worst in the nation based on a written test covering rules of the road.
Spending more than a few hours riding (or even driving) around Baltimore and Maryland in general, it becomes clear that people do not drive well. They tend to be not courteous and generally unsafe. Especially as it often pertains to bicyclists. Well, the study confirms that at least they are also ignorant of the rules of road!
Biking in Baltimore