M
| Street | Route | Communities | Landmarks | Notes |
|---|---|---|---|---|
| Manor Road | Old York Road to Glen Arm Road | Phoenix | ||
| Marriottsville Road | Runnymeade Road to Frederick Road (in Howard County | Owings Mills Randallstown |
Patapsco State Park | Exit 83 off I-70 in Howard County. Transverses 3 counties: Baltimore, Carroll, and Howard. |
| Martin Boulevard | Pulaski Highway to Chesapeake Park Plaza | Middle River | ||
| McCormick Road | Beaver Dam Road to International Circle | Hunt Valley | McCormick Road (Baltimore Light Rail station) | Part of Bus Route 9 |
| McDonogh Road | Reisterstown Road to Liberty Road | Pikesville Owings Mills Randallstown |
McDonogh School | Continues past Reisterstown Road as Cradock Lane and past Liberty Road as Greens Lane. When traveling northbound between Winands and Lyons Mill Roads, going straight continues onto Painters Mill Road. A right turn is required to continue onto McDonogh Road. McDonogh Road crosses over Interstate 795 and the Baltimore Metro Subway; at this point, a Metro Subway station was once proposed, but was never constructed due to community opposition. Public transportation was also proposed on fought on a different part of McDonogh Road in 2005 when a GBBI plan to extend Bus Route M-8, then the line serving the Liberty Road corridor, to Owings Mills along McDonogh and Painters Mill Roads was opposed by residents of the portion between Liberty and Winands Roads. |
| Merritt Boulevard | Baltimore Beltway to Sollers Point Road | Dundalk | BCPL North Point branch | Exit 39 off Baltimore Beltway |
| Merrymans Mill Road | Poplar Hill Road to Jarrettsville Pike | Cockeysville Jacksonville |
Continuation to Maryland Route 943 (Warren Road), though not designated as such | |
| Middletown Road | Steltz Road to York Road | Parkton | Exit 31 off I-83 | |
| Milford Mill Road | Rolling Road to Reisterstown Road | Milford Mill Pikesville |
Milford Mill Academy Milford Mill Metro Subway Station |
Continues as Slade Avenue. A parallel section off Reisterstown Road known as Old Milford Mill Road is part of its original route. There is also an "Old Milford Mill Road" near Liberty Road. Part of route of Bus Routes 52, 54, and 77. |
| Monkton Road | York Road to Troyer Road | Hereford Monkton |
Route 138 becomes Shepperd Road east of NCRR trail | |
| Mount Carmel Road | Lower Beckleysville Road to York Road | Hereford Armacost |
Exit 27 off I-83 | |
| Mount Wilson Lane | Reisterstown Road to dead end | Pikesville | Ner Israel Rabbinical College |
Read more about this topic: List Of Roads In Baltimore County, Maryland