 Maryland Route 646 | ||||
|---|---|---|---|---|
| Prospect Road | ||||
 Maryland Route 646 highlighted in red | ||||
| Route information | ||||
| Maintained by MDSHA | ||||
| Length | 3.31 mi[1] (5.33 km) | |||
| Existed | 1946–present | |||
| Major junctions | ||||
| South end |  MD 543 near Ady | |||
| North end |  MD 136 at Prospect | |||
| Location | ||||
| Country | United States | |||
| State | Maryland | |||
| Counties | Harford | |||
| Highway system | ||||
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Maryland Route 646 (MD 646) is a state highway in the U.S. state of Maryland. Known as Prospect Road, the state highway runs 3.31 miles (5.33 km) from MD 543 near Ady north to MD 136 at Prospect. MD 646 was constructed as a section of MD 543 in the early 1930s. That section of MD 543 and the road originally marked as MD 646 swapped numbers by 1946.