When New York City’s first elevated opened in 1868, it marked the first foray of rapid transit in the United States. Rapid transit was an effort to increase speed and capacity by separating trains from other modes of transportation.
By the time Washington’s Metro opened in 1976, the new modern systems being constructed in the United States had a different basis in their design. Not only could trains travel at higher speeds, but they were intended not mainly for inner city transportation so much as for suburb to center city commutes. As a result, they were designed with longer distances between stations.
Station spacing seems to be the largest determinant of average schedule speed: the measure of the average velocity of a train from end to end of a line, including station stop time. Compare the average schedule speed of Metro and the five lines to the average schedule speed of other heavy rail transit operators.
I also conducted an analysis of all heavy rail transit lines in the United States. See the chart below to compare the speeds of different services to each other.
Two particular services are worth mentioning: The 42nd Street Shuttle in New York, and Chicago’s aptly named Skokie Swift, now known as the Yellow Line. Both of these services have only two stations, one at each end. Because there are no intermediate stops, their average schedule speed is very high.
Of course actual speed plays a role too. The PATCO Speedline, which has the highest average schedule speed of US heavy rail systems, has a top speed of 65 mph (reduced from the design speed of 75). In second place, BART has a top speed of 80 mph.
Note, the initial charts included in this analysis omitted the Broad Street Subway Express in Philadelphia. This error was accidental, and it has been corrected.