U.S. Route 301 crosses the Potomac River from Virginia into Maryland, cuts through Charles and southern Prince George's counties, and in Bowie joins U.S. Route 50, with which it overlaps through the Annapolis area and over the Chesapeake Bay Bridge onto Maryland's Eastern Shore. US 301 then shoots northeastward along the upper Shore and into Delaware. US 301's southern Maryland segment serves as part of an I-95 bypass between Richmond, Virginia and Baltimore. The entire portion of US 301 in Maryland is divided with at least four lanes.