There are some 15 double tracked rail lines entering Boston; that is more than sufficient to provide a base for the finest mass and rapid transit system in the world, particularly for a city with exceedingly few rail freight deliveries. Right now, the MBTA uses 60% of its urban-core rail right-of-way exclusively for just 17% of its rail patrons.
The set of double tracks in the Somerville rail corridor are used to ferry riders on the Lowell Commuter Line between North Station and stations lying in the exurbs of greater Boston and Eastern Massachusetts. Additionally, Amtrak's Downeaster service to and from Portland, Me. uses a portion of the Lowell Line and a freight delivery to Boston Sand and Gravel travels over these tracks once a week.
The Amtrak and Freight Use
Amtrak's Downeaster makes six daily round trips. It enters Massachusetts on the tracks of the Haverhill Commuter Line, then, because of single track issues on a portion of that line, uses a short connecting line to move onto the tracks of the Lowell Line.
A project to double track the upper portion of the Haverhill Line will soon be complete and should alleviate the need to continue running the Downeaster in the current Lowell Line rail corridor. It should as well alleviate the need to run Haverhill Line express trains in this same corridor due to the same single track issue.
The single freight use is by Pan Am Railways, which has freight rights on most of the lines running north out of Boston, even though they are owned by the MBTA. Pan Am Railways, just like CSX, has been consolidating their service areas away from Boston, and now have few customers remaining inside I-93. I believe circumstances are such that they would willingly release their interest in these lines if arrangements are made to satisfy remaining contractual commitments to customers.
The weekly freight use on this line occurs in the late evening to avoid interference with commuter train service. It originates in Dover, NH and can just as well use the tracks of the Haverhill Commuter Line to arrive at its destination in Charlestown. A minor shift in scheduling would be needed as the Haverhill line has a short single track section through Malden, and thus any late running commuter trains would need to be cleared before the arrival of the freight train, at close to midnight.
The single track conditions around Malden, though heretofore handled sufficiently with signaling, should be remedied, just as that condition is currently being attended on the northern portion of this line. The MBTA has not tackled this due to the need for modifying two stations (a result of shortsighted planning when they were constructed, just like the GLX plan today). Another option on this subject, would be to cut back the night time commuter service schedule. The cost effectiveness of such service seems questionable, and a cut back would avoid any conflict with freight service on the line.
Lowell Commuter Service
Turning to the heaviest use of the Somerville/Medford rail corridor, the Lowell Commuter Service could be diverted to the same tracks used by the Haverhill Commuter Line for ferrying its patrons through the urban portions of Boston into the CBD. Diverting the Lowell service would clear the set of double tracks out to Winchester for use in the MBTA's urban transit network. The close proximity of the Lowell Commuter tracks to the Haverhill Commuter tracks northwest of Boston presents this as a solution. Note the map below.
The closest proximity of the lines to each other lies just north of the Lowell Line's Anderson/Woburn Transit Station, however diverting before this stop is imprudent as the station has received considerable investment as an intermodal transit center with convenient access from I-93 and bus service. Looking south of the station, the density of development precludes a low impact connection to the Haverhill Line, however a reverse connection turning immediately northeastward out of the Anderson/Woburn Station is not only the closest connecting point but also a very low impact route of approximately 1.6 miles. The junction would be one mile north of the Reading Station stop.
Note that dubbing it a 'reverse' connection is mostly just terminology. Once stopped in the station, the train's entry point is moot. The locomotives for the MBTA commuter trains are push-pull. They typically push all the way into Boston and pull all the way back. Thus, here they would start out pulling from Lowell Station, then start pushing to leave Anderson/Woburn, and push all the way to Boston as is done today; the return trip would be reversed. There is no additional time incurred for a switch from pull to push or vice-versa. There is no retracing of the route, as the connector is encountered immediately upon leaving the station. And, as for total trips times, see below.
With adequate signaling and its brief length it is feasible to use a single track for this connection without service interference, but plans for double tracking in the future should not be precluded. Beneficial is that the added curve out of the station on the connecting line is of no consequence to the trip time of trains as they will already be at reduced speeds approaching and leaving the station. The MBTA is currently double tracking the Haverhill Line from Reading northward which will give the line passing ability from the junction point on that line to Wyoming Hill, one stop away from Malden.
Diverting the Lowell Line service to the tracks of the Haverhill Line from Reading through to Boston should also push the MBTA to attend the several 'at grade' road crossings in this corridor. There are currently over 40 daily runs on this line, enough to warrant grade separations at most all road crossings, therefore this is an expense which is due to be made regardless of any additional service on the line.
This shift will end commuter service to four Lowell Commuter Line stations below Anderson/Woburn, but the effects are mitigated by other developments. The next station south is Mishawum, the least used station on the Lowell Line and only 1.6 mile by road from the Anderson/Woburn Station. Several miles farther south are two stations only a half mile separated from each other and roughly two miles north of the final station of West Medford.
Put It Back
The original GLX plan stretched service across the Mystic River into West Medford, but has since been struck from the project. The elimination of the West Medford portion was due in part to opposition fearing a defacing of the existing rail road bridge over the Mystic River Parkway and Mystic River, which would need to be altered or abutted by a new bridge to handle the addition of two tracks.
The proposal to reallocate use of the existing tracks, instead of adding tracks, eliminates any need to alter the bridge, bringing the West Medford station back to life. This station improves the overall justification for the project, if the goal is to convert automobile trips to rail trips, and not just the shifting of current public transit riders. The MBTA was too willing to eliminate this station to think the former is their goal.
With the addition of West Medford to the urban rail system, it and Winchester, immediately to the north, will have more frequent transit service than they received from the Lowell Commuter Line, a positive change for these areas. An Orange Line extension to Winchester could easily be made in the future when warranted.
Commuter Trip Times
Another bonus from the diversion of the Lowell Line are that its riders will have four fewer station stops, or, alternatively, the MBTA could have two of the Haverhill stations, which the Lowell train would now pass, changed to be serviced by the Lowell Line, thus sharing the time savings among the two lines. As well, the Lowell Line will have capacity freed up, which is advantageous as extensions into New Hampshire are anticipated.
The distance to North Station from Anderson/Woburn will increase by 2.17 mile (includes the connector), and former Mishawum pickups will now go the extra 1.6 miles to A/W, but this time will be more than mitigated by fewer station stops.
A concern raised is that speed limits imposed (likely due to the many grade level crossings already referenced) on the tracks from Reading to North Station will greatly diminish the trip times currently achieved on the Lowell Line, such that ridership will greatly decline. If this were true, it would certainly be a consideration affecting the balance of benefits and costs. However, a review of the published schedules for the two lines indicates this concern is unfounded.
The graphic below is a composite of posted schedules for the Lowell and Haverhill Lines from Anderson and Reading Stations, respectively, to North Station. A non-stop run from Anderson to North Station is listed at 21 minutes, that would include any decrease in speed while passing stations. The same run with 3 station stops is 27 minutes.
With no non-stop run showing for Reading to North Station, it'll need to be derived by deducting delays for station stops from its average run time of 30 minutes. If the 6 minute delay for 3 stops on the Lowell trip is conservatively assumed to have been rounded up, in other words the total trip time for such runs is in fact 26.5 minutes, we'll use of a 5.5 minute delay for its 3 stops.
We then can double that number to 11 minutes (6 stops) for deducting from the average run time posted for Reading to North Station, giving 19 minutes for a theoretical non-stop run. Presuming any further trip-time 'rounding' on schedule times cancel each other out, the Reading to North Station run has a 2 minute advantage in trip time over the Anderson to North Station run.
The roughly 2 mile distance to be traversed between Anderson and Reading stations should take 3.5 minutes based on the deduced average rate of speed. The 2 minute savings on the Haverhill tracks to North Station deducted from the 3.5 minute crossover time for Lowell trains leaves a theoretical 1.5 minutes time addition to a rerouted Lowell Line, which if that alone were the final result would be a reasonable accommodation given the totality of benefits across the system.
However, the additional time saved for Lowell Line riders includes at least 5.5 minutes (perhaps 6), that had been used for 3 regular stops which no longer exist. Thus, if all Lowell trains run directly from Anderson to North Station on the new route, all, but the very few which were express, will cut their trip times by 4 minutes, a considerable benefit for those riders.
Most likely scheduling would require that the Lowell trains take over at least two of the stops which the Haverhill trains currently handle, thus producing no net change in trip time for that line. The Haverhill Line will then benefit by a 4 minute time savings with two less station stops between Reading and North Station, or perhaps only one if it is found to be more beneficial to have both lines stop at Malden Station.
While this configuration is feasible given the current frequency of traffic on the lines, it will be necessary to schedule carefully; this is made primarily so because of the single track condition which currently exists south of Wyoming Hill. As stated above the single track condition above Reading has already been attended. When scheduling and signaling can no longer adequately accommodate demand on the lower section, expenditures to add a single additional track to it will be far more cost effective than the route now being taken with the GLX.
And once again, eliminating the many 'at grade' crossings along the Haverhill Line should be a priority for the MBTA, a mandate which the State should make. That condition being left unaddressed makes the extravagant waste of funds on an ill fitting, and yet seemingly (though misguidedly) politically correct, transit project all the more reprehensible.