MBTA ridership time/distance charts

I posted a chart in reference to Alon Levy's post about commuter rail ridership distribution a few weeks left. He pointed out that the same treatment could be given to commuter rail in other cities, like Boston. Results as follows:

Note: Old Colony includes the Greenbush Line unless otherwise noted. "Eastern" is the Newburyport/Rockport Line, which is the old Eastern Railroad. Traveler distributions for its branches are pretty similar.

This chart is the same as the ones for New York. The ridership levels are lower, of course, as are the distances. Only 5% of Boston's ridership comes from beyond 60 km, while 25% of New York's ridership travels that distance. Now, since I collected these data, I can run them for other variables. Here, for example, is the same chart shown by minutes instead of kilometers:

A couple of notes: travel times were calculated for the shortest scheduled travel time, and are shown from each outlying station to North and South Stations. Service to Back Bay is 5-6 minutes shorter on the non-Old Colony South Side lines.

There's a bit more variation here. Notably, the Lowell Line shows up as having shorter travel times, since it is a relatively short line with relatively fast speeds. And the Worcester Line, which is one of the longer lines, stands out as having longer travel times, although it achieves relatively good ridership despite this. One other way to view these data is to look at average speed by line. Do note that this chart is not cumulative, but show the fastest available service for each station:

Note: these times are for inbound trains only; the Worcester Line does have some outbound trains which average 38 mph from South Station to West Natick.

Note how the Providence Line and the Lowell Line are by far the fastest in the system. The express from Mansfield to Boston averages 45 mph; the run to Back Bay averages nearly 55. The Lowell Line, which has speed limits of 70 mph, averages over 40 mph on express runs from North Billerica (less from Lowell which has a long, slow section through a yard south of the station. These lines have more spread-out stations and are mostly grade-separated; except for two grade crossings in West Medford there are no public grade crossings on the Lowell Line and none between Boston and Providence.

The Fitchburg Line is relatively fast (especially for express trains) although it's length means that trip times are long. It benefits in ridership by not paralleling a direct highway to the city and it is slated for speed upgrades which should shave 10 minutes off travel times. Other line speeds are relatively abysmal (Haverhill might see improvements based on ongoing trackwork), with a particular finger pointed at the Worcester Line.

The MBTA will soon seal the deal to buy the whole of the line to Worcester. I wouldn't hold my breath on increased speeds. The T could have purchased higher speed cars and electric motors for the Providence Line. Did they? No. The line to Worcester is double-tracked in its entirety (except for a stretch through the Allston yards, but that should be remedied) and has four grade crossings (indeed, the only four grade crossings between Boston and Springfield) in total. There is no reason that 80 mph line speeds would be difficult to attain in short order, and 110 in the longer range. But there's little about higher speeds and shorter times coming from upstairs.

There's potential for ridership with trip times equal to or better than driving. Worcester is slightly off the Turnpike, so the 45 mile trip takes closer to an hour. At rush hour, there's usually traffic adding another fifteen or thirty minutes. And the tolls—$3.60 each way—add to the cost of driving significantly, as it's the only line where the driving option is tolled. Sub-hour trip times should be easy, and 60 mph, 45 minute trip times not out of the question (beyond that, connections to Springfield and Amherst would be much more feasible if trip times to Worcester were halved). That would be progress for the state's second largest city. … As long as the T actually serves Worcester (and doesn't just build a park-and-ride on the outskirts as they seem to like to do).