In 1991, just as the final two-lane section of US 50 was falling into severe disrepair, Vienna was bypassed to the northeast, completing the dualization of the eastern section of US 50. The drawbridge was then dismantled, and portions of the old road were designated MD 731. The designations have been rolled back over time, however, and MD 731 is no longer signed. The 1990s also saw two extra lanes added to the John Hanson Highway in both directions as it was upgraded to enter the Interstate Highway System, being granted the Interstate 595 designation. However, the Interstate 595 shields were never installed on the highway; although the sign gantries installed during the upgrade contain space for the I-595 shields to be installed, this never happened to prevent motorist confusion, and as a result the designation is only used internally. The freeway portion was extended to the Eastern Shore, from the Chesapeake Bay Bridge east to the US 50/US 301 split in Queenstown. The US 50/US 301 portion of the Blue Star Memorial Highway was upgraded to a freeway mostly during the late 1980s and early 1990s; prior to this it was only a divided highway with several local roads intersecting it. After being upgraded, many of these intersections became sharp right-in/right-out ramps.