The MBTA commuter rail lines are laid in such a way that there’s an inherent tension between providing local service and providing longer-distance intercity service. It’s less apparent on the Providence Line because the intercity component, i.e. Boston-Providence, follows immediately just from serving the suburbs between Boston and Providence, but elsewhere there are greater problems. Good local service would have intense frequency in the inner portions of commuter lines; unfortunately, most lines only meet right next to the termini, reducing the opportunities to use interlining to create high-frequency inner segments.
Good local service also needs many infill stops, while good intercity service needs higher speeds. My proposals for the Providence Line essentially go with intercity service needs, justified by the facts that Providence is a major anchor, that high top speeds are possible on the line, and that the line should also host high-speed trains. Fortunately, the Providence Line has an opportunity for more intense local service using the Stoughton Line to add frequency; while this would end up overserving Canton Junction and Route 128, Readville and points north would get adequate peak service, and acceptable off-peak service. This is not as true on other lines, especially on the North Side, in which there’s a tradeoff between fast service to outlying cities and good service within Cambridge and Somerville.
Of course, the issues I’ve focused on in my previous post on the subject – electrification, high platforms, modern rolling stock – are useful for both. A fast-accelerating EMU could connect Boston with the various terminals at the same time as today’s express trains while making all stops as well as some extra infill stops. The problem comes from trying to fit trains into a clockface schedule. On a few lines, for example the Lowell Line, it’s actually easier to close very lightly used stations (Mishawum) or stations that are very close to other stations (Wedgemere).
Another issue is outbound extensions. With some, there’s so little traffic beyond the current terminus, or sometimes even beyond a point slightly closer than the current terminus, that the decision should be easy. This contrasts with the MBTA’s approach of proposing more and more outer extensions. With others, the intercity functions make extensions more reasonable, within certain bounds. I believe the following list of judgment calls would be reasonable:
1. Providence Line: no extension required – the line’s natural end is Providence. If Rhode Island wants to provide a low-frequency glorified parking shuttle from Wickford Junction and the airport to Providence, it’s its business, as long as it doesn’t muck up timetabling that’s based on Providence-Boston service.
2. Stoughton Line: an extension to Taunton would work, and possibly even to New Bedford. I’m iffier on Fall River, which has stronger commute ties to Providence; however, Providence-Fall River requires too much new infrastructure to be easy.
3. Franklin Line: either extend it to Milford (which may be easier to serve from the Worcester Line), or cut it back to Franklin. The Forge Park terminus is close to a lot of office park jobs, but the local road network is so sprawled out that it’s not worth the extra few minutes of travel time.
4. Fairmount Line: building infill stations is an excellent idea, though it should be coupled with increase in frequency and service level to make them more useful. One way to improve off-peak frequency is to route all Franklin Line trains along this line, and perhaps add supplementary trains that turn at Readville. The advantage of this is that the Fraknlin and Fairmount Lines used to be one railroad, with a grade-separated crossing over the Providence Line; in contrast, the junction at Readville is flat, making it more operationally cumbersome to have trains cross from one line to the other.
5. Needham Line: no extension necessary – the only possibilities would dismember the line in favor of much lower-density suburbs than Needham. Better would be to eliminate the line entirely and put Needham on a branch of the Green Line, and restore past plans to extend the Orange Line to West Roxbury. This would dismember the line too, but in favor of more service to dense areas rather than less. I don’t know what’s Needham’s commute tie to West Roxbury, but its commute tie to Newton and Brookline is fairly strong, 1,300 vs. 3,400 to Boston and another 3,400 in-town.
6. Worcester Line: Worcester is the natural terminus, so no extension should be entertained.
7. Greenbush Line: Greenbush is the natural terminus. The greatest urbanization is on the coast rather than along the railroad, and this limits the line’s usefulness.
8. Kingston/Plymouth Line: the natural terminus is downtown Plymouth, slightly farther out from the current Plymouth station, which should be renamed North Plymouth or just closed for lack of utility. In addition, Plymouth sends Boston 2,565 commuters, and Kingston only 797. Either the roles of Kingston and Plymouth should be switched – Plymouth would get served all day and Kingston would get only supplemental rush hour trains – or the Kingston branch should be closed, and replaced with a station on the main line.
9. Middleborough Line: for ordinary regional traffic, the line should be marginally cut back, to place the Middleborough station at the center of the town. In fact, there’s a dropoff in commute volume south of Brockton, and yet another south of Bridgewater; Middleborough is a fine terminus, but is not a proper anchor like Providence, Worcester, or especially Plymouth. On the other hand, there’s some potential for intercity traffic to Cape Cod, capturing some commuters as well as vacationers heading the other way.
10. Fitchburg Line: the MBTA’s proposed extension to Gardner looks weak to me, though not completely daft. That entire region of northern Worcester County has much stronger commute tie to Worcester than to Boston, in similar vein to the issue of Fall River’s connection to Providence. The commute tie to Framingham, as in the MBTA plan to have a branch leaving Framingham toward Leominster, is even weaker than that to Boston. It would be better to have a regional line connecting Gardner to Worcester, which would also have the advantage of taking a much more direct route than the freeway network; connecting Fitchburg and Leominster would require more work and compete with I-190 directly.
11. Lowell Line: here an outbound extension is natural and desirable, since Nashua and Manchester have a nontrivial commute tie to Boston and are significant cities in themselves, though as with Cape Cod this would be more of an intercity line. New Hampshire had a plan for such an extension, but it was killed by state Republicans early last year. This is unfortunate, since Nashua in particular has a less than great freeway connection to Boston, which a fast electric train could consistently beat.
12. Haverhill Line: Haverhill is a natural terminus. Although Rockingham County has a strong commute tie to Boston, the greatest part of it comes from very sprawled out towns near I-93, far from the line.
13. Newburyport/Rockport Line: the split at Salem allows natural interlining to give the towns with the strongest commute ties the most frequency. An additional branch to Marblehead would be prudent, providing even more frequency to Lynn, Chelsea, and additional infill stops in Revere. At the north end, Portsmouth looks like a fine intercity terminus, but in fact that part of Rockingham County is a marginal commute market to Boston, better than that feeding into Haverhill but much worse than the I-93 sprawl.
Not discussed above are station placement and infill stations. Station placement is relatively easy, since bad cases like Westborough and the aforementioned Middleborough and Kingston look obvious on a map. In addition, such office park stations with terrible ridership as Mishawum and River Works are already treated as such, so almost all trains skip them and their ridership is very low, making them clear candidates for closure.
Infill stations are harder. The problem is that on the North Side, the four lines split too early. This means that, while infill stations are possible, it’s hard to give them adequate frequency. Short-turning local trains could help somewhat, but is the most difficult on the two lines that serve Cambridge and Somerville, the Lowell and Fitchburg Lines. It’d be much easier to do this with Lynn (which already benefits from interlining and would benefit even more from a Marblehead branch) or Malden (which has the Orange Line).
That said, the Lowell Line might be able to support a local train to Winchester and an intercity train that makes zero or one intermediate stop between North Station and Winchester. The commute market is not great at this distance, though; Belmont has 3,100 Boston-bound commuters, and 290 inbound riders at its two commuter rail stations. A reroute of the Fitchburg Line along the Charles River Branch through Watertown might get more ridership; it would be slower, but it has zero intercity function, compared with strong potential at and east of Brandeis. To succeed, high frequency and short station spacing are required. For an example using the Charles River Branch, see here.
On the South Side, the Worcester Line begs for infill between Yawkey and Newtonville, but some of the people it would serve may already be riding the Green Line. The Green Line doesn’t perfectly parallel the line the way the Red Line parallels the Old Colony Line or the Orange Line parallels the Providence Line and the Haverhill Line, though, and there’s room for two or three stations serving Allston, Brighton, and Nonantum. On the other hand, some of these stations would compete with Watertown somewhat, and are less ideally placed in that the Worcester Line has an intercity function whereas the Fitchburg Line doesn’t.
Finally, another unmentioned issue is the effect of rapid transit extensions, especially of the Green Line. The extension plan to Somerville, which the state is obliged to build as one of many mitigations for the traffic induced by the Big Dig, is effectively a replacement for Lowell Line infill in Cambridge and Somerville; the line would only really need one infill stop to connect to the Green Line, and perhaps the Green Line would need to be extended to West Medford, if not to Winchester. That said, the interaction with rapid transit is more complex than this, and I will discuss it more in a future post.