MD 198 was widened to on Montgomery Street in Laurel in 1948. When the US 1 Laurel Bypass—today the northbound lanes of the U.S. Highway on Second Street—was completed, the highway was extended east one block on Montgomery Street to the new bypass in 1950 and 1951. In 1963, MD 198 was removed from Montgomery Avenue and placed on its Gorman–Talbott one-way pair through Laurel in 1963. That same year, a new piece of highway was created from Van Dusen Road to Ninth Street to connect the one-way pair with Sandy Spring Road. That same year, MD 198 was extended over the course of MD 602 to Fort Meade. The first portion of MD 198 to become a divided highway was along a new alignment from Sweitzer Lane to Van Dusen Road. This highway was built concurrent with I-95 and the I-95–MD 198 interchange in 1970 and 1971.