What's cross-town traffic?

CROSS-TOWN traffic may be applied to Washington D.C. Most of the streets in W.D.C. run East/West or North/South. Most of the city is in the North West quadrant. The street signs are mostly marked as to which quadrant you are in. Some major horizontal streets, like Constitution Ave. are in two marked quadrants. The District of Columbia is a precisely measured 10 miles on each of the four sides. The Potomic River lies in Virginia and Maryland and mianders through the center of the city.