An ironic fact about freeways is that while they are designed to connect towns, they effectively partition them as well. A look at the south suburbs of Baltimore tell the story. The area between I-95, MD-100, and the Chesapeake Bay is criss-crossed with eight interstate-standard freeways. Interstates 95, 195, 695, 895, and 97, along with Maryland routes 10, 100, and 295.
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The area is served by MARC and the MTA Light Rail, however the stations in this area are predominantly park-and-ride. Home prices in these neighborhoods are significantly lower than in other parts of Howard and Anne Arundel Counties. And crime is not uncommon in these suburbs.
Further south, 95 and 295 cut through DC suburbs in Prince George's, but are currently only crossed by the Capital Beltway. Though this area is of similar size and similar geography, the population is much higher than northern Anne Arundel and eastern Howard counties. House prices are comparable, but they have been rising lately, particularly around the Metro stations.
I blame much of this on street connectivity. When the landscape is drawn and quartered like it has been in Baltimore's southern suburbs, it naturally has a negative effect on street connectivity. Lack of street connectivity can lead to higher incidence of traffic accidents, longer response times for emergency vehicles, and greater traffic jams.
Of course, this is a very unscientific and opinion based overview of how lots of highways can ruin an area. I'm sure there are lots of people who think Glen Burnie is a much better town than Hyattsville, so I encourage comments here.