From the invaluable Via Meadia blog on the American Interest's website comes the news, first reported by the Washington Post, that a startup company called Bridj is setting up a bus service in the District of Columbia using big data to establish where consumers are seeking rides. There would be no established bus stops; demand would determine where the bus would pick people up and where it would drop them off. Bridj has already started up a similar service in the Boston area.

What caught my eye was this sentence: "A ride from Coolidge Corner to Kendall Square, which Bridj founder Matt George says would likely [take] 42 to 55 minutes on the Massachusetts Bay Transportation Authority, has taken 15-18 minutes on his company's buses." Coolidge Corner is an intersection in Brookline, not far from the Boston city limits; Kendall Square is in east Cambridge, just across the Charles River from Boston. It struck me that 42 to 55 minutes was an awfully long time to travel that distance, so I clicked on my iPad map to see how long the journey would be by other means. Answer: 13 minutes to drive 3.5 miles, 58 minutes to walk 2.7 miles. Yes, you could walk the distance just about as rapidly as a slow mass transit ride. And unless your time is not worth a lot in dollar terms, a $5 Bridj ride that takes 15-18 minutes is a lot more attractive option than a $2-and-something T ride that takes 42-55 minutes. A 30-to-36-minute commute is a lot more pleasant than an 84-to-110-minute commute.

Why is the mass transit commute so long? The reason is that Boston's subway and fixed rail lines, like those in the other five "legacy" metro areas which account for over half the nation's fixed-rail transit passengers (New York, Philadelphia, Washington, Chicago, San Francisco), were located to radiate outward from downtown locations. To get from Coolidge Corner to Kendall Square on Boston's T, you have to take the green line trolley over 10 stops to Park Street, a station facing Boston Common, then transfer to the red line subway and take two stops to Kendall Square. Presumably variance in frequency of trains accounts for the 42 to 55 minute time range.

The lesson: fixed-rail transit is far less flexible than bus transit and far less attractive except for those traveling to downtown locations. The six legacy metro areas all still have large downtown working populations — significantly larger than any other metro area in the United States — but even there mass transit doesn't do much for you if you commute from one place to another which are both outside the central business district. But fixed-rail mass transit has an emotional appeal to those with a central planning impulse who would like to have everyone live in high-rises adjacent to subway stations.