 The remaining portions of MD 20 and MD 718 were removed from the state highway system around 1999.MD 151's interchanges with Wharf Road in Sparrows Point and with MD 20 and Bethlehem Boulevard in Edgemere were built by 1963.The state highway's partial interchange with Merritt Boulevard was constructed in 1969 and the crossover interchange with I-695 was built in 1971.