Boston has had subways since 1901, making it the sixth oldest subway system in the world. The network is nicknamed the "T" because the Massachusetts Bay Transportation Authority uses an encircled T for Transportation as its logo. What's really interesting about the T, though, is its color-coding system. The four main subway branches were assigned hues in 1965, and each color had significance. The northwest-to-southeast route became the Red Line because it runs through Harvard and their school color is crimson. The west-to-north route became the Green Line due to the Emerald Necklace parks it passes through. The southwest-to-north was called the Orange Line because it goes under a road formally named Orange Street. Last but not least, the northeasterly Blue Line is called that because it travels under Boston Harbor. This is really fascinating to me for some reason; I suppose it's because I didn't expect subway line colors to have etymologies.
Adam Aleksic, an incoming freshman at Harvard University, has been described as the internet's sixth most famous etymologist. He has disturbing interests in linguistics, vexillology, geography, board games, limericks, and law, and he loves writing about himself in the third person.
The Etymology Nerd