Orange, Blue, and Green Lines have no physical rail interconnections with each other, though they are all operated by the MBTA and exchange passengers in shared stations.) The second network forms the Boston area portion of the North American rail network, and provides commuter rail, intercity passenger rail and freight rail services. Although the two networks are essentially unconnected, they do in some places run alongside each other in the same right of way. Interchange stations allow interchange of passengers, but not trains, between subway and commuter rail services. Parts of the subway network also use former common user rail rights of way. Subway network Boston has the oldest subway system in North America, with the first underground streetcar traffic dating back to 1897. Today the whole subway network is owned and operated by the Massachusetts Bay Transportation Authority (MBTA). In the early 1960s, the then-newly-formed MBTA hired Cambridge Seven Associates to help develop a new brand identity. Cambridge Seven came up with a circled T to represent such concepts as "transit", "transportation" and "tunnel." Today, Bostonians call their rapid transit network "the T", and it is the fourth busiest in the country, with daily ridership of 549,000 trips excluding the Silver Line bus. This compares with the Washington Metro's 910,100, the Chicago 'L''s 596,300, and Los Angeles's 126,900, but is overshadowed by New York City's 6.0 million average daily weekday trips. The one-way fare is $2.40. Monthly commuter passes, and day and week visitor's passes are also available for purchase. There are four subway lines in the metropolitan Boston area: the Red Line, Green Line, Orange Line, and Blue Line. The colors of each line have a symbolic meaning: the Blue Line runs under Boston Harbor; the Red Line used to terminate at Harvard University (whose school color is crimson); the Orange Line used to run along Washington Street, which was once called Orange Street; and the Green Line runs along parts of the Emerald Necklace into the leafy suburbs of Brookline and Newton. The Green Line is actually four different lines; it starts as one trunk line but then splits into four different branches, the B (Boston College), C (Cleveland Circle), D (Riverside) and E (Heath Street) trains. Because the split is only relevant on the outbound direction of travel, one may take any train inbound, but when going outbound one must be careful to board the correct