Greenmount Avenue south of North Avenue becomes virtually deserted mostly because it's too far east from Downtown's major north south routes. Greenmount Avenue becomes a neighborhood street but has the potential to carry more traffic. The route that Greenmount travels doesn't take you to any destinations worth going to (unless you're driving a patty wagon) but I-83 does.
I-83 aka the Jones Falls Expressway aka the JFX does make that Downtown journey that city and county dwellers use and use it they do. There is a vacant parcel of land where an interchange can be created to connect Greenmount Avenue to I-83 just south of the Cemetery near Belvidere St. (yes that's how it's spelled) If you're traveling south on Greenmount Avenue you will be automatically be rerouted onto southbound I-83 or "North President St." (more about that later) by making a southwest curve that is the current Belvidere St. You will also have the option of exiting to travel northbound on I-83. If you travel southbound you will go under a bridge that is northbound I -83 traffic and will be in the left lane of traffic on I-83. Greenmount Avenue below the new interchange will be narrowed to reflect the neighborhood nature of the street and will be renamed "Old Greenmount Avenue" (I don't think it's original either.)In addition to receiving Greenmount Avenue traffic I-83 will receive changes of its own. First of all the southbound interchanges with Maryland Avenue and St. Paul St. will be closed and those wishing to exit I-83 before the Greenmount interchange may do so at the newly redesigned North Avenue/Mount Royal Avenue interchange. This will no doubt create relief to the over crowded southbound streets that lead Downtown such as Howard St., Maryland Avenue, and St. Paul St. Having closed off these interchanges will not effect accessibility to Penn Station because the ramps land you below Penn Station. Speaking of Penn Station the troublesome ramp from Charles St. to I-83 north will remain open but with pedestrian "countdown" signals and wider sidewalks.
Just south of the new interchange comes Preston St. and I'm sure you know where this is going but I'll explain it anyway. President St. which is I-83 below Fayette St. will be extended northbound to Preston St. The interchanges in between and including Fayette St. and Preston St. will be converted into traffic signals which takes care of I-83 "cutting the city in half."
Now this will obviously have a drastic effect on all neighborhoods effected. I'm banking that the effect will be positive for all effected neighborhoods.First and foremost is Greenmount West whose southern border is the location of the new interchange. I'm unsure whether this will open up or close off Greenmount West but being part of Station North it will see its day in the sun as it expands eastward into Greenmount West.Next there's Johnston Square, Johnston Square has long been plagued by the ills of urban decay. Something that slips people's minds all too often is that the elevated I-83 is the only thing dividing it from Mount Vernon. With the elimination of the elevated highway Johnston Square will integrate itself into the Downtown landscape of Mount Vernon and redevelopment and reinvestment will turn this diamond in the rough into a gem. It may go all the way into Oliver where "Preston Place" is being developed on vacant lots that may be the first of many redevelopment projects there. Just south of Johnston Square is the area known as "Penn Fallsway." Here there are prisons with great architecture and parking lots. East of Penn Fallsway sits Old Town Mall, Forest St. Apartments, Somerset Homes, Douglass Homes, and LaTrobe Homes. The city is coming up with a master plan for the Old Town Mall area which includes the demolition of Somerset Homes and is looking into the possibilities of demolishing the other public housing complexes as well. This along with the surface level parking lots of Penn Fallsway creates acres of land ripe for redevelopment as an expansion of Downtown with high density mixed use buildings and a link to quickly gentrifying Middle East and Washington Hill neighborhoods. Mount Vernon will become more walkable as its streets won't be clogged with through traffic. I don't believe businesses in the area will suffer because the excess traffic isn't caused by patrons.