MD 157 was assigned to the highway in Sparrows Point in the early 1990s and extended through Dundalk to its present northern terminus in the late 1990s.

MD 157 heads north as Peninsula Expressway, a four-lane divided highway that crosses over I-695 and has a half-cloverleaf interchange with southbound I-695 in the direction of the former Francis Scott Key Bridge.

The state highway crosses over the CSX rail spur between Baltimore and Sparrows Point before reaching Merritt Boulevard.

[4][5] Meritt Boulevard was constructed as a four-lane divided highway from North Point Road, which was then part of MD 20, to the center of Dundalk in 1960.

[12][13] The portion of Peninsula Expressway south of the Bear Creek bridge was brought into the state highway system as MD 157 around 1991.

[16][17] On May 27, 2016, the Maryland State Highway Administration closed the drawbridge that carries MD 157 across Bear Creek due to "significant corrosion".