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.