US 222 in Maryland used to extend down to MD 7 in Perryville. In 1972, the south end of US 222 was cut back to US 40 in Perryville, with MD 222 replacing the route along Aiken Avenue between MD 7 and US 40. AASHTO approved rolling back the southern end of the US 222 designation from US 40 in Perryville to US 1 in Conowingo at their April 1995 spring meeting. The Maryland State Highway Administration proposed and AASHTO approved the redesignation of US 222 to MD 222 from US 40 in Perryville to US 1 in Conowingo in February 1996; however, the new designation had already been enacted officially and marked publicly in 1995.