If the Orioles and Nationals both make the World Series, it will almost certainly be called “The Beltway” series. As someone who lived in D.C. for a few years this irks me a little bit, because technically speaking it would not be a “Beltway Series.”
The Royals and Cardinals played an “I-70” World Series, as I-70 connects those two cities. The Yankees and Mets played a “Subway Series” because you can take the subway from one park to another. If the Angels and Dodgers meet, it will be a “Freeway Series” for the same reason. Obviously the Cardinals and Royals took charter planes from city to city and obviously the Mets and Yankees didn’t actually take the Subway to get to the ballpark. But one could, if one wished, take the mode of transportation mentioned in the name from one ballpark to another.
Not so the Beltway. There are two of them, actually. The Capital Beltway, which is I-495 (and in parts, just 495/95) and the Baltimore Beltway, which is I-695. They don’t meet. They merely encircle their respective cities. Navigationally speaking, you’d be better served calling a Marlins-Tigers World Series “The I-75 Series” than you would using either Beltway as a signifier. If you tried to take the Beltway from D.C. to Baltimore, you’d forever be traveling in a circle, except when you’re at a complete stop near Tysons Corner.
Of course, this is one of those deals where it doesn’t matter what is correct. They’re going to call it the Beltway Series if it happens, even if it’d be better to call it the DC/MD-295/B-W Parkway Series. That’s because it’s way harder to put “DC/MD-295/B-W Parkway Series” on a T-shirt.