High Quality Content by WIKIPEDIA articles! Maryland Route 235 (MD 235) is a state highway in the U.S. state of Maryland. Known as Three Notch Road, the state highway runs 30.63 miles (49.29 km) between its southern intersection with MD 5 in Ridge and its northern intersection with MD 5 near Mechanicsville. While the southern part of the state highway is a quiet rural road, the northern part of MD 235 is a four- to six-lane divided highway connecting Naval Air Station Patuxent River (NAS Patuxent River) and the Washington, D.C. metro area in conjunction with MD 5. Due to the military base, the state highway is part of the National Highway System between the main entrance to the facility at MD 246 in Lexington Park and the northern terminus at MD 5. MD 235 is also the longest state highway in Maryland to run entirely through one county.