MBTA Mode Shares
As a followup to my claim in my first post about improving the MBTA about the low mode share of commuter rail for trips into Boston, here are some figures about commuter rail use, by sector. All numbers exclude commuters from inner suburbs and from Boston itself, since those would use the subway. Only Boston-bound commuters are included. I’m providing wider and narrower numbers, wider numbers corresponding to the entire sector defined by a commuter line and narrower numbers including only towns within reasonable range of a commuter station.
All commuter rail numbers come from the Bluebook and are averages as of February 2009, from page 74; be careful not to use numbers from the map on page 70, as they inflate the ridership on the Providence Line. All commute market numbers come from the 2000 census; I do not believe commuting patterns have changed so radically as to significantly alter the picture.
Update: we obtain the following table, explained below (see also computation error fix for Haverhill):
| Line | Wide market | Narrow market | Riders | Share of wide | Share of narrow |
| Old Colony | 43,587 | 34,934 | 20,907 | 48% | 60% |
| Providence, Stoughton | 23,297 | 17,490 | 11,719 | 50% | 67% |
| Franklin | 14,899 | 12,747 | 7,043 | 47% | 55% |
| Worcester | 19,997 | 15,581 | 7,479 | 37% | 48% |
| Fitchburg | 16,544 | 13,358 | 5,883 | 38% | 44% |
| Lowell | 15,551 | 11,912 | 5,586 | 36% | 47% |
| Haverhill | 19,196 | 16,902 | 8,922 | 46% | 53% |
| Newburyport, Rockport | 26,926 | 25,534 | 13,230 | 49% | 52% |
Old Colony Lines (including Greenbush)
Commute market (wider): all of Plymouth County; Cohasset, Weymouth, Randolph, Holbrook, and Avon towns in Norfolk County
Commute market (narrower): including only the above Norfolk County towns and Plymouth County’s towns of Abington, Bridgewater (including East and West), Brockton, Hanson, Hingham, Hull, Kingston, Lakeville, Middleborough, Plymouth, Rockland, Scituate, and Whitman
Commuter volume (wider): 43,587
Commuter volume (narrower): 34,934
Inbound commuter rail ridership: 12,065 (excluding JFK-UMass, Quincy, and Braintree)
Extra transit use: 7,244 subway and commuter rail boardings in Quincy and Braintree beyond those accounted for by those two towns’ commuter market; 1,598 commuter ferry riders, mostly from Hingham
Mode share: 60% of the narrow market, 48% of the wide market
Providence and Stoughton Lines
Commute market (wider): all of Rhode Island, all of Massachusetts’ Bristol County, and the towns of Sharon, Canton, Stoughton, and Plainville in Norfolk County
Commuter market (narrower): the three Norfolk County towns omitting Plainville, all of Rhode Island’s Providence and Kent Counties, and Massachusetts’ Bristol County’s towns of Attleboro (including North), Mansfield, Easton, Norton, and Seekonk
Commuter volume (wider): 23,297
Commuter volume (narrower): 17,490
Inbound commuter rail ridership: 11,719
Extra transit use: none
Mode share: 67% of the narrow market, 50% of the wide market
Franklin Line
Commute market (narrower): Norfolk County’s towns of Dedham, Westwood, Norwood, Walpole, Norfolk, and Franklin
Commute market (wider): the above plus the towns of Medfield, Medway, and Wrentham
Commuter volume (wider): 14,899
Commuter volume (narrower): 12,747
Inbound commuter rail ridership: 7,043
Extra transit use: none
Mode share: 55% of the narrow market, 47% of the wide market
Worcester Line
Commute market (wider): all of Worcester County except Fitchburg, Harvard, Westminster, Gardner, and Leominster; Wellesley; and Middlesex County’s towns of Natick, Ashland, Framingham, Marlborough, Hudson, Hopkinton, Holliston, and Sherborn
Commute market (narrower): Wellesley; Middlesex’s above counties omitting Hudson, Holliston, and Marlborough towns; and including only Worcester County’s towns of Southborough, Westborough, Northborough, Shrewsbury, Grafton, Worcester, Auburn, and Millbury
Commuter volume (wider): 19,997
Commuter volume (narrower): 15,581
Inbound commuter rail ridership: 7,479 (west of Newton only)
Extra transit use: none, as all Green Line usage is accounted for by Newton commuters
Mode share: 48% of the narrow market, 37% of the wide market
Fitchburg Line
Commute market (wider): Worcester County’s Fitchburg, Harvard, Westminster, Gardner, and Leominster towns; Middlesex County’s Belmont, Waltham, Wayland, Weston, Concord, Sudbury, Acton, Maynard, Stow, Lincoln, Littleton, Boxborough, Ayer, and Townsend towns
Commute market (narrower): Worcester County’s Fitchburg and Leominster only; Middlesex County’s above towns, omitting Stow, Townsend, Wayland, and Sudbury
Commuter volume (wider): 16,544
Commuter volume (narrower): 13,358
Inbound commuter rail ridership: 5,883 excluding Porter
Extra transit use: two local bus lines (70, 70A) to Waltham with 4,343 trips in each direction and two more express lines (553-4) with a combined 681 trips (none serving just Waltham, but also Newton or Cambridge), but conversely much of the ridership Waltham generates is non-commuter student traffic
Mode share (assuming neutral Waltham effect): 44% of the narrow market, 36% of the wide market
Lowell Line
Commute market (narrower): Middlesex County only, towns of Winchester, Wilmington (half, shared with Haverhill Line), Woburn, Billerica, Lowell, Chelmsford, Tewksbury, and Dracut
Commute market (wider): the above, plus the Middlesex County towns of Dunstable, Westford, and Tyngsboro, and all of New Hampshire’s Hillsborough County
Commuter volume (wider): 15,551
Commuter volume (narrower): 11,912
Inbound commuter rail ridership: 5,586 excluding West Medford
Extra transit use: none – if anything, this line is missing more of its potential coming from its inability to serve Medford well under current commuter rail paradigms
Mode share: 47% of the narrow market, 36% of the wide market
Haverhill Line
Commute market (narrower): Middlesex County’s towns of Melrose, Stoneham, Wakefield, Reading, North Reading, and Wilmington (half, shared with Lowell Line); and Essex County’s towns of Andover, North Andover, Lawrence, and Haverhill
Commute market (wider): the above, plus Essex County’s towns of Boxford, Middleton, Groveland, and Lynnfield
Commuter volume (wider): 19,196
Commuter volume (narrower): 16,902
Inbound commuter rail ridership: 5,343 excluding Malden
Extra transit ridership: Malden’s two subway stations get 8,375 riders beyond the commute market, but they could be coming from people from Everett and Medford – let’s just add the number of parking spaces, which is 976, plus one half of the remaining ridership at Oak Grove, representing Melrose and Stoneham’s share, which is 2,603 (total bus ridership in Malden and the cities to its north is 3,394 in each direction, and I’m willing to believe 2,603 of this is from north of Malden)
Mode share: 53% of the narrow market, 46% of the wide market (update: a previous version of this post gave slightly lower numbers coming from forgetting to add the 976 subway parking spaces to the imputed ridership)
Newburyport and Rockport Lines
Commute market (wider): all of Essex County except the towns of Andover, North Andover, Lawrence, Haverhill, Boxford, Middleton, Groveland, and Lynnfield
Commute market (narrower): Essex County omitting, in addition to the above, the towns of Amesbury, Georgetown, Essex, West Newbury, Topsfield, and if one wants to be very narrow then also Saugus
Commuter volume (wider): 26,926
Commuter volume (narrower): 25,534 with Saugus, 22,999 without
Inbound commuter rail ridership: 8,821 excluding Chelsea
Extra transit use: no rail, but likely high bus ridership coming out of Lynn – total North Shore ridership is 4,409 in each direction excluding the 430, which is assigned to the Haverhill Line, and some lines that do not serve subway stations (429, 431, 435, 436, 451, 455, 465, 468)
Mode share: counting commuter rail only, 38% of the narrowest market and 33% of the wide market; counting also buses, 52% of the narrow market including Saugus and 49% of the wide market
Conclusion
The best-performing sectors capture about half the ridership of their general area of service and two-thirds of the ridership coming from the towns served by transit. Except for the Providence Line, this requires heavy use of subways and buses; the high contribution of commuter buses north of Boston suggests that better regional rail service, with more useful frequencies and integration between the CharlieCard and Charlie Ticket, really would make a difference, effectively railstituting the trip to Boston and allowing redirecting the buses to feeder service. The worst-performing lines only capture a third of the market, and for those there’s less that can be done; regional rail improvements would help, especially with regards to speed and reliability, but often those areas are too sprawled out.
Another conclusion is that for the purposes of constructing timetables for an electrified, FRA-free MBTA, we should ignore current ridership patterns, and instead look at the volume of commuting. The southwesterly slice serving Providence is not special; it just gets higher mode share on commuter rail since the service levels are higher than elsewhere. A 15/30 timetable on each line or branch (counting Kingston and Plymouth as one, but not any other split) would more or less approximate market demand; it would still underserve the South Shore, but the South Shore has ferry use and subway use, and therefore there’s no lower-level service to replace with good commuter rail.
A third conclusion is that it matters whether commuter rail can serve shorter trips or not, such as trips from Waltham, Medford, Malden, Lynn, and the Fairmount Line area. Those towns and neighborhoods have much larger volumes of commuters heading toward Boston than farther-out towns. This observation favors the regional rather than intercity interpretation of commuter rail, sacrificing speed in order to improve coverage in the innermost suburbs and in outer-urban neighborhoods.
On no line is express service a good proposition except when it’s downright intercity service, such as high-speed rail to New York via Providence, or even intercity trains to Maine or deep into New Hampshire. The problems coming from runtimes that aren’t a short turnaround time less than an even multiple of 15 minutes should not be fixed with express trains, but with closing some stations that aren’t necessary (such as River Works and Mishawum), and building more infill together with the North-South Rail Link, redistributing lines in such a manner as to maximize efficiency. For example, if the branch from Lynn to Marblehead is reactivated, then even with several additional infill stops, trip time from North Station to Marblehead would be about 22 minutes, which together with time gains from the tunnel (travel time through the rail link should be a hair lower than a turnaround time) would allow mixing with the Worcester Line. Currently it’d be difficult to do Worcester-Boston in 55 minutes even under best operating assumptions, and impossible with infill stations, but with the rail link and through-service to Marblehead, the limit would be closer to 1:01, and this allows a few infill stops in Brighton.
What’s driving all of this is the fact that there isn’t all that much demand mismatch. The South Side lines have a larger (wide) market than the North Side lines, but the difference is much smaller than the difference in ridership, and decreases even further if one lets the subway take care of certain parts of the South Shore. This means that, in terms of planning, all lines should be upgraded and should receive ample attention toward service levels, and in terms of operations, through-service should be based on infrastructure capabilities and scheduling constraints rather than on service demand matching.
Pedestrian Observations 
Alon–
Mass transit mode share when measured at the metropolitan level is quite low (maybe in the 10% range); however, your local-market analysis reveals that when a reasonable mass transit option is available it is well utilized, by local market standards.
While the numbers may be different across metropolitan areas–and studying local-market mode-shares scaled to the quality of transit offerings sounds to me rather like a potential research grant application–this suggests to me that the low mass transit ridership figures at the metropolitan level is due in no small part to the fact that at that scale one’s agglomerating both served and unserved local markets.
Suggesting two planning options for the average mass transit agency: (1) Optimize existing services, so as to realize the greatest possible mode capture in served local markets, and (2) Extend lines to offer service in previously unserved local markets. In other to optimally pursue the latter option, though, the extensions would have to maximize new market service at minimal cost. Extending line termini one new station at a time, especially when those stations are park-and-rides, would be the wrong way to go about this.
When pursuing line extensions, it’s thus best to pursue routes that lie roughly halfway between served markets.
To clarify, I’m looking only at people who work in Boston. People who work in the central city tend to take transit at much higher rates than people who do not. Put another way, my entire writing on the MBTA already gives up on a large majority of travel need; there’s too much competing highway capacity and job sprawl and not enough thick markets to make routes to suburban job centers work today. The best that can be done is relocating stations to urban cores and promoting development nearby in order to anchor more commercial construction, which would then lead to reverse-peak ridership and eventually to providing justification for circumferential routes.
In other words, when I say a market is underserved, what I mean is that a market heading toward the Boston CBD is underserved. Even something like the Providence Line (reasonably high speed, good track maintenance, double track, semi-decent peak frequency) would do a world of good on many of those lines.
This is some interesting data, because it gives a pretty good idea of how much growth is possible if service is improved. If the Providence Line is at 67% of the narrow market, that means that there’s probably not a huge need to build lots of fancy infrastructure to massively increase service, and that some fairly minor improvements and faster trains could bring the service level up to 4 tph, which will be enough to serve current demand.