Maryland Route 4, also known as MD 4, is a major highway in the state of Maryland. It runs approximately 30 miles from Washington, D.C. to Calvert County, connecting several communities along the way. The route serves as an important corridor for commuters and travelers, providing access to various local attractions and amenities. The highway begins at the District of Columbia line and travels through areas such as Prince George's County and Southern Maryland. It features multiple lanes in urban sections and transitions to a more rural setting as it approaches its southern terminus. MD 4 is vital for regional transportation and economic activity.