| State: | MD |
| Type: | MD |
| Route: | 808 |
| Map Custom: | yes |
| Alternate Name: | Main Street |
| Length Mi: | 2.34 |
| Length Round: | 2 |
| Tourist: | Old Main Streets Scenic Byway |
| Established: | 1972 |
| Direction A: | South |
| Terminus A: | Ridgeville Boulevard in Mount Airy |
| Direction B: | North |
| Terminus B: | near Mount Airy |
| Counties: | Carroll, Frederick |
| Previous Type: | MD |
| Previous Route: | 807 |
| Next Type: | MD |
| Next Route: | 810 |
Maryland Route 808 (MD 808) is a state highway in the U.S. state of Maryland. Officially MD 808A and known as Main Street, the state highway runs 2.34miles from Ridgeville Boulevard north to MD 27 within Mount Airy. MD 808 follows the Carroll - Frederick county line for a portion of its length near its southern terminus. The county line portion is considered to be in Carroll County for maintenance purposes. MD 808 is the old alignment of MD 27 through Mount Airy. A portion of Main Street was paved by 1910; the sections south and north of the town center were constructed in the early 1910s and late 1910s, respectively. MD 808 was assigned to Main Street after MD 27's bypass of Mount Airy was completed in the mid-1970s.
MD 808 begins at an intersection with Ridgeville Boulevard, the original route of U.S. Route 40 (US 40), in the Ridgeville section of Mount Airy. Main Street continues south as a municipal street to an intersection with MD 27 just north of that highway's interchange with Interstate 70 and US 40 (Baltimore National Pike). MD 808 heads north through residential subdivisions as a two-lane undivided road following the Carroll - Frederick county line on top of a ridge. South of Sunset Avenue, the state highway fully enters Carroll County. MD 808 continues north through the Mount Airy Historic District, where the highway crosses paths with the former right-of-way of the Mount Airy Loop of the Baltimore and Ohio Railroad. The state highway passes Buffalo Road, which forms the Carroll - Frederick county line for several miles, and Waterville Road before leaving the town limits. MD 808 passes through the hamlet of Dorceytown before reaching its northern terminus at an intersection with MD 27 (Ridge Road).
The unincorporated community of Ridgeville and the town of Mount Airy developed on top of Parr's Ridge, a north - south ridge that separates the Monocacy River watershed and Frederick County to the west from the Patapsco River watershed and Carroll County to the east. The ridge was originally crossed by the Baltimore and Fredericktown Turnpike at Ridgeville and the B&O Railroad at Mount Airy. By 1910, a paved road connected the turnpike and the Mount Airy Loop of the railroad. The ridge-top road north 1.5miles from Mount Airy and south toward Montgomery County was designated for improvement as one of the original state roads by the Maryland State Roads Commission in 1909. The state road was paved as a 14feet wide macadam road from the turnpike in Ridgeville south to the Howard County line in 1913. The highway from the center of Mount Airy north through Dorceytown was completed as a 15feet wide concrete road in 1920.
MD 27 from its southern terminus in Germantown north to Westminster was originally designated MD 29 when the first state-numbered routes were established in Maryland in 1927. In 1934, US 29 was extended into Maryland over what had previously been MD 27 between Silver Spring and Ellicott City; the Germantown - Westminster and Silver Spring - Ellicott City highways swapped numbers. MD 27's interchange with I-70 was constructed when US 40 was relocated as a four-lane divided highway through Ridgeville in 1953 and 1954. MD 27's bypass of Mount Airy was constructed from Dorceytown south to Ridgeville Boulevard in 1972. The I-70 interchange was reconstructed as part of I-70's upgrade to Interstate standards in 1975. The bypass was completed from Ridgeville Boulevard south to the I-70 interchange in 1977; MD 808 was marked on Main Street by 1978.
The entire route of MD 808A is in Mount Airy. The state highway follows the Carroll - Frederick county line between its southern terminus and a point south of Sunset Avenue. The county line portion is considered to be in Carroll County for maintenance purposes. The remainder of the highway is in Carroll County.
MD 808B is the unsigned designation for Spring Mills Road, a 0.23miles spur from MD 27 that preserves a section of old alignment of MD 27 south of Westminster.