| State: | MD |
| Type: | MD |
| Route: | 100 |
| Alternate Name: | Paul T. Pitcher Memorial Highway |
| Map Custom: | yes |
| Map Notes: | Maryland Route 100 highlighted in red |
| Length Mi: | 22.38 |
| Length Round: | 2 |
| Established: | 1970 |
| Direction A: | West |
| Terminus A: | in Ellicott City |
| Junction: |
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| Direction B: | East |
| Terminus B: | in Pasadena |
| Counties: | Howard, Anne Arundel |
| Previous Type: | MD |
| Previous Route: | 99 |
| Next Type: | MD |
| Next Route: | 103 |
Maryland Route 100 (MD 100) is a major east - west highway connecting U.S. Route 29 (US 29) in Ellicott City (just north of Columbia) and MD 177 (Mountain Road) in Pasadena. MD 100 also connects to Interstate 95 (I-95), US 1, the Baltimore–Washington Parkway (MD 295), and I-97. The highway connects Howard County to the west with Anne Arundel County and the Chesapeake Bay to the east. MD 100 also provides access to the Baltimore–Washington International Airport (BWI) and the Arundel Mills shopping mall.
The eastern section of MD 100 in Anne Arundel County is known as the Paul T. Pitcher Memorial Highway. The name comes in dedication to Paul T. Pitcher, an Anne Arundel County executive, who originally conceived the highway.[1]
The route begins as a six-lane divided freeway at US 29 near Ellicott City. There are then interchanges with MD 108, MD 104, Snowden River Parkway and MD 103.
At the junction with I-95, the road narrows to four lanes. Then MD 100 intersects with US 1 followed by an exit for the Dorsey station along MARC's Camden Line. It then crosses the Baltimore-Washington Parkway.
MD 100 then intersects with MD 170 (Telegraph Road) where the road becomes 6 lanes. Then the road junctions with Interstate 97 near Hanover and reduces down to 4 lanes before crossing MD 2. Between Glen Burnie and Jacobsville, MD 100 serves as a bypass for MD 177, and has interchanges with MD 10 and MD 607.
The road ends by merging back into MD 177.
Maryland Route 100 began in the 1970s as two separate roads, both having the MD 100 designation. The first was known as the Mountain Road Extension, stretching between Governor Ritchie Highway and the old Maryland Route 3, now Interstate 97. The second was built as a short spur between the newly constructed Interstate 95 and US 1 in Elkridge.[2] The eastern section, originally known as the Mountain Road Bypass, was constructed east of Ritchie Highway in the late 1970s. MD 100 was completed west of I-97 to I-95, thereby connecting the two roads, in 1994, but it was not completed in its entirety to US 29 until November 1998. A portion of the route between Exit 1B-C and Exit 2 was constructed earlier than the rest as an at-grade boulevard, on the right-of-way of the future eastbound lanes; this section was eventually upgraded.[3]
The construction of the route near Lake Waterford Road severed the original road between Baltimore and Annapolis: the Baltimore-Annapolis Boulevard, signed in part as MD 648. The physical road ends at a pair of dead ends on either side of the right-of-way; MD 648 follows Lake Waterford Road between Baltimore-Annapolis Boulevard and MD 177 before rejoining its original path.
The route was to be part of the Baltimore Outer Beltway, a proposed freeway that would have encircled parts of the Greater Baltimore area and provide a route parallel to the Baltimore Beltway. MD 100 represents the major portion that was built; US 29 between MD 100's terminus and US 29's own northern terminus at Maryland Route 99, four miles (6 km) in length, is another portion. The Outer Beltway was projected beyond MD 99 to run through Howard and Baltimore Counties and intersect MD 140, Interstate 83, US 1, and Interstate 95 before terminating at US 40 northeast of Baltimore.
MD 100 has fourteen auxiliary routes: five in Howard County, eight in Anne Arundel County, and one in both counties.