Friday, November 1, 2019

What's up with the taxi queue at Logan?

Early Monday morning, on Twitter, Cambridge City Councilor Jan Devereux posted this photo of the taxicab line at Logan Airport:
Then she went to check out the Uber/Lyft line and it was no better:
By 1:30, others reported that the cab line was an hour long.
What's going on here? Where are all the taxis? Where are all the Ubers? Why are people arriving at the airport after midnight then waiting an hour for a ride home? What can we do about this?

It's not really a simple answer. Please, though, follow me down a rabbit hole.

Logan airport is not a hub airport (okay, not really: Delta and especially JetBlue are doing their best to create a hub, but it still is mostly an origin-destination airport). This is a matter of geography: because it is tucked away at the northeast corner of the country, the airport mostly handles passengers flying in one direction, south or west, either on direct flights, or to other domestic hubs (although international travel has increased markedly in recent years, and JetBlue even has a bank of later domestic flights to accommodate connecting passengers).

Boston's flights can be grouped in to three main types: short haul flights to non-hub cities, short-haul flights to hub cities, and long hauls, both domestic and international. Only the first group operates without geographic constraints which dictate that flights can only arrive and depart at certain times of day. Non-hub short-haul flights, mostly on JetBlue and Delta (to places like AUS, BUF, RDU, MKE) are spread more evenly throughout the day, because they don't have to make connections at hubs. Hub-based flights within the eastern half of the United States (say, as far as MIA, DFW and MSP). These flights account for many of the early departures, but few leave Boston after early evening. They don't arrive in Boston until mid-morning, but are the bulk of the last flights arriving later in the evening. Because of these travel patterns, Logan has a lot of early and late flights: in the morning, people want to get to a connecting hub for the first "bank" of connecting flights, and in the evening, flights have to leave the connecting hub after the last bank has occurred.

(Not all airlines utilize banking at hubs—Southwest most notably runs continuous hubs—and there are pluses and minuses to each method, about which I won't go into too much depth here. But basically, banking decreases fleet utilization and increases congestion at hub airports since flights arrive and depart all at the same time, followed, in some cases, by periods of relatively low flight activity, but passengers have much shorter connection times at hubs since connections are coordinated. It's actually something like a pulse system for buses, except that airports have finite numbers of vehicles which can arrive and depart at any given time, and longer dwell times. As airlines have consolidated, hubs have grown and seen more frequent banks such that they are now closer to continuous operation, especially at large airports like Atlanta and Chicago. See how this is a rabbit hole? Also, when I say people want to connect to the first bank, I mostly mean airlines, no rational human being wants to be on a flight departing at 5:15 a.m.)

Then there are longer-haul flights. Transcons have to deal with time changes, cycle times, and the fact that flights generally don't depart or arrive between 1 a.m. and 5 a.m. local time. So they arrive from the West Coast either as redeyes between 5 and 10 a.m., and then turn to depart between 6 and noon, or as day flights, arriving in the afternoon or evening. Thus, in addition to the overnight lull, there are basically no transcons which arrive in or depart Boston during the midday. International flights (mostly TATLs) generally are redeye flights going out, leaving Boston in the evening, and return during the middle of the day, arriving in the afternoon. All told, Boston has demand throughout the day, but particularly high demand for flights arriving later in the evening.

For instance, O'Hare and Atlanta, the two busiest airports in the country (by number of aircraft movements), have 29 and 24 flights scheduled to arrive after 11 p.m., respectively. Boston has 39. After 11 p.m., Boston is basically the busiest passenger airport in the country (about tied with LAX), and possibly the world (since in many countries, airports have noise regulations which limit late night flights). Yet at the same time, there are few flights departing Boston. The airport has only 14 scheduled departures after 11 p.m., and only six of these are domestic flights (all are JetBlue E190s, so they're small planes). There is basically zero demand for passengers to get to the airport late at night. This creates a demand imbalance for ground transportation: there's a lot of demand to leave the airport at midnight, but almost no one who wants to go there.

Here are some charts of the approximate number of airline seats arriving and leaving Boston. I adjusted for the typical arrival time at the airport (60 minutes for domestic, 120 for international) and assumed it would take 30 minutes for the average international passenger to clear customs.



(Note, the seat numbers for arrivals and departures don't exactly match because each day at Logan is not identical and this was a snapshot of a day. This is total seats available, not total passengers, and is also a rough estimate based on plane sizes at different times of day, but should show general trends well.)

So, it's clear that there is a good deal more demand to get to the airport in the morning, which doesn't even out until around 9 a.m., various points of imbalance during the day, and then, starting around 7 p.m., significantly more demand to leave the airport.

A couple of personal anecdotes can illustrate this. The first illustrates the imabalce in the morning. Back before the Big Dig was completed (and, in fact, pre-Silver Line, and back when the airport had half the traffic it has today), when I was going to college, getting to the airport was, perhaps, worse than today. It involved both the elevated Central Artery and then the Sumner/Callahan tunnel complex: a trip to or from the airport to downtown could take an hour (which is, of course, not much different than it is now). For several years, however, the Ted Williams Tunnel had been open to commercial vehicles only. The connecting highways were not yet complete, so this was a way to keep the local streets from getting overrun by people trying avoid the congestion.

From Newton, where I grew up, my father came up with a solution, especially for early morning departures. He would drive me to South Station. Rather than risk the airport traffic, I'd get in a cab for the usually $10 or $12 trip under the harbor in the tunnel only cabs could use. Early one morning, I got in a cab at South Station and told the driver I was going to the airport. He quoted the fare: "$20" and didn't turn on the meter. What I should have done is say "I'll pay you whatever the meter quotes at the end of the ride, so it's in your best interest to turn it on now," but I was 18 and hadn't quite figured that out, so at the airport, I paid him $20, noted his medallion number, and immediately reported it.

A month later my dad got a check for $20 from the Boston Police (which oversee taxi medallions), along with a note that the taxi driver had been given a stern talking to that he was never to refuse to turn on the meter for a trip within the city.

But I understand why the driver was reticent to take the fare. He would get to the airport and have two (bad) decisions. One would be to go to the taxi pool and wait in line for an fare back to the city: a long line, because there is much less demand going in to the city at 7 a.m. than there are taxis arriving at the airport. The other would be go cross back downtown without a passenger, but still incur the cost of driving, as well as the tunnel toll (which was one-way inbound at that point), with no passenger to pay it. Still, because of redeye arrivals from the West Coast in the morning, there is some traffic for cabs that do make it to the airport going back, although they have to cycle through the cab pool (or the Uber/Lyft pool) before their next fare. Even now, if you take a cab or a ride-hail vehicle to the airport in the morning, the driver is probably not particularly happy taking the fare.

The second example was an extreme example of the late-night issue. I was flying back from SLC and the flight was delayed several hours. Originally scheduled in at 11:30 (plenty of time to catch the Silver Line downtown and take the T home), the plane was more than three hours late, and didn't arrive in Boston until about 2:30. The airport was empty. Yet a 757 had arrived with 200 passengers, and no one was making the trip at that point to pick us up. So we all converged on the cab stand, but there wasn't a cab in sight. Immediately, people started self-pooling: it was clear that if we all took our own cabs, the line wouldn't clear for hours. "Who's going to Brookline?" "I'm going to JP, that's close!" "I'm going to Concord." "I'm going to Lexington, let's share." Every few minutes, a stray cab would roll up, three overtired strangers would pile in, and the line would get slightly shorter. I found a cab pretty quickly, but imagine those at the back of the line may have seen the sun rise.

Finally, here's a picture of the departures level at Terminal A at 8 p.m. this past week.


Delta's last domestic flight leaves at 7:45 (to MCO) and the last hub-based flight leaves at 6:56 (for ATL). Two international flights leave around 8:30. At this time, it's a ghost town. Note: if you're picking someone up at the airport in the evening, plan to meet them on the upper level, and note that Terminal A is a great place to wait without having State Police harass you. (Terminal B was pretty quiet, too.)

Here are scheduled arrivals and departures, by carrier, at different times of day:


Note: not all regional flights appear to be in this sample, for instance, there are no Cape Air flights shown after mid-evening, when Cape Air flies several late flights out of Boston, but these flights are minimal as far as number of arriving passengers is concerned.

Notice how departures peak in the morning, then lull in the midday, and then have a secondary peak in the evening, before domestic departures (except for JetBlue) tail off quickly after 7 p.m. International carrier flights are clustered arriving in the afternoon and leaving in the evening. But there is a clear imbalance for flights arriving and departing the airport.

In any case, this has been a problem for years, and it's a structural issue pertinent to Logan Airport based on the airport's geography on both a macro and micro scale. On a macro scale, the geography of the airport at the corner of the country means that, late in the evening, flights feed into it but don't feed out. On a micro scale, the airport's geography encourages taxi/app-ride/ride-hail use (I'll call these taxis, for simplicity). The constrained location means that parking costs are high, because demand for parking outstrips supply. The proximity to areas with high trip generation (downtown, and high density areas nearby) means that taxi costs are often significantly lower than a day's parking cost ($38) in the garage. The combination of these factors push many people to use taxis.

Much of the day, taxi supply roughly matches demand, and there is a minimal delay for these services. But this breaks down at the beginning and end of the day, especially in the evening. Once again, Logan's geography comes into play. While the airport is close to the city geographically, it is expensive to get to for a taxi driver. When there is high demand for fares back to the city at 1 a.m.—especially once buses have, for the most part, stopped running—there is negligible demand to get to the airport, or even East Boston in general, so to pick up any fare would require the driver to deadhead to the airport.

Unless a driver happens to pick up a stray fare to East Boston, this requires a driver to travel several miles, and to pay the cost of the tunnel toll. Once at the airport, there is no promise that the trip home will be lucrative enough to cover these costs. They might get a $50 fare to a far-flung suburb. But it might only be a $15 fare to a downtown hotel or, worse, to Revere or Winthrop, meaning a driver would then have to drive back home—likely through the tunnel—and foot the bill for the toll both ways. Moreover, this is the end of the day for most drivers: except on a Friday or Saturday night, there is only so much demand for rides after 1 a.m. For many drivers, the potential upside of getting a decent fare from the airport doesn't make up for the potential downsides, especially when the alternative is shutting off the app (or taximeter), driving home, and going to bed an hour earlier. There is a high disincentive to be in the last group of taxis at the airport: a driver might get one of the last passengers, but if not, there is not likely a job for several hours when the first redeye flights start to trickle in around 4 a.m. There is little incentive for taxicab drivers to go to the airport during this dwindling time, so demand is only met by drivers already in East Boston who need a fare back to the city.

This is not an easy issue to solve. It also shows why Uber and Lyft are basically just taxis: they are subject to the same supply and demand issues that affect the rest of the market. Alas, they're providing the same service: a chauffeured ride from Point A to Point B. And the airport is pretty much the only place that cabs still have a foothold, partially because matching passengers to specific vehicles is quite inefficient with large groups, like you might find at an airport. This has been a recent point of contention at LAX, which consolidated its taxi and ride-hail facilities away from the terminals (as Logan is planning). It hasn't gone particularly well to start, but I would venture to guess that there are similar supply and demand issues at LAX. (As several people have pointed out, the buses there are running much more smoothly, too.)

Of course, at LA, there is a temporal aspect to the complaints about #LAXit. Most of the issues are in the evening. Los Angeles has more balanced operations, with plenty of departures in the evening, both redeyes to the East Coast and transcontinentals, mostly TPACs but some TATLs as well. There is probably both more demand for cabs in the evening because LA is on the opposite side of the country as Boston, and also because most of the transcon redeyes leave before 11 p.m., and most of the later flights are international, which are fed more by connecting travelers and by passengers arriving at the airport much earlier. Thus, for the actual demand for taxis, there is a similar, if less pronounced, demand compared with Boston.

I scraped Twitter for #LAXit from the first few days and it seems clear that the issue is mostly in the evening.


But back to Boston. Here's what the Logan cab pool Twitter feed (because of course Logan's taxis have a Twitter feed) looked like last Sunday. There was a cab shortage by 8 p.m., and the late night arrival issue was foreseen by 10 p.m. It wasn't a surprise. It is a market issue.


Is this feed a bot? Certainly not! Note the wrong months, typos, misspellings, random numbers of hyphens and use of quotations. The one thing that seems constant is the use of the word "need" when the airport has a cab shortage (with various qualifiers like all-caps or exclamation marks). I'm pretty sure it's a guy standing by the taxi pool furiously typing tweets into the Twitter machine. So, I decided to scrape the feed (about 60,000 tweets), and code each tweet by whether it included the word "need" or not, to get a very rough estimate of the frequency of taxi delays at Logan.

From the charts of arrivals and departures above, we would assume that the airport would generally need cabs mid-afternoon, as well as in the evening. If we chart the arrival and departure relationship and the Twitter feed's need for cabs together, and we shift the need for cabs back 1:15 (probably due to actual behavior of arriving passengers), voila, they match pretty darned well.


A few other notes on the need for cabs:

  • There is more demand on Sundays (36% of Tweets include the word "need"), followed by Mondays, Thursdays and Fridays (28%), with the least demand on Saturdays (20%)
  • The cab shortage is generally higher in the summer than the winter (and highest in May, June, September and October, while lowest in December, January and February), and it has been particularly high this year. In fact, the only higher demand for cabs at the airport was in February of 2015. I wonder why.


TL;DR: it is definitely getting harder to get a cab at the airport, especially during certain times of the year and at certain times of day. And when flights are delayed, this is exacerbated. Departing passengers generally still get to the airport on time, but arriving passengers get in later, meaning the cab shortage is even more acute. Which leads to situations like the one which occurred earlier this week at the start of this post, which may have taken you nearly that long to read

So what can be done about it? Well, Uber/Lyft could use their surge features to increase the cost of a trip to the point where it would make economic sense for drivers to come to the airport at this time of day. But that might double or triple the cost of a ride, so while it is a very market-based solution to the problem, it is not consumer-friendly. It (and taxi starters) could do a better job of pooling rides, and moving the Ubers and Lyfts to the same site might make pooling easier there. A very low-tech idea might be to figure out where vehicles are going and, at high-demand times, put people into lines based on regions to help them self-pool. This might nibble around the edges on the demand side, but it doesn't help supply. It turns out that Lyft and Uber are not a magic panacea to mobility: they are subject to the same supply and demand issues as the rest of the world. And if the answer is pricing, it's not a great answer, especially since prices might have to go up significantly to provide enough supply or suppress demand enough to satisfy market equilibrium, especially after midnight when there are really no other options available.

One solution, I think, is that rather than trying to bring supply to the demand, we should move the demand to where there is more supply: get people, en masse, downtown. This requires a magical invention: the bus. While the supply of hire cars is not limitless (there are only about 1800 taxicabs in Boston, and probably far fewer are active today, and many more Ubers and Lyfts, but a finite number), it is significantly less constrained on the other side of the Harbor. Instead of trying to entice drivers to come to the airport, we could instead move riders to where are there are more cars. Most riders are going north, west or south of the airport, and need a ride through Downtown Boston anyway. The bus might not be that appealing to a traveler at 1 a.m., but neither is a 45 minute taxi ride. This basically takes what LA is doing, and extends it a couple of miles.

The MBTA runs the Silver Line until 1:15 a.m., which could easily bring passengers to South Station, where catching a taxi or ride hail vehicle is easier than at the airport. Massport and the T, however, do a poor job of advertising these late buses, both with signage telling passengers the hours as well as real-time information about the buses' whereabouts (important especially if you are unsure if the last bus has left). But these are easy issues to solve. The bus real-time data is available: I have no issue pulling it up on mbtainfo.com, for instance.

Not helpful, especially if you're trying to figure out if the last bus has left, or even deciding if it's worth waiting in a cab line versus waiting for the bus.

And Massport could put up static signage:

NO CABS? NO PROBLEM!
GET A CAB ACROSS THE HARBOR

MBTA BUS TO SOUTH STATION

SKIP THE LINE — SAVE MONEY

BUSES EVERY 8-15 MIN UNTIL 1:15 AM
ADDITIONAL BUS AT 2:30 AM

And as I've written before, with some minor schedule tweaks, the T could use the Silver Line 3 returns from Chelsea to supplement this service even later, and keep one bus in service to make an extra round trip to provide service until 2:30 when, on most nights, the planes have all landed. Alternatively, or in addition, Massport could continue its Back Bay Logan Express bus later in the evening and into the early morning (or even 24/7), providing late night trips to the taxicab-rich parts of Boston when there are cab shortages at the airport (and perhaps even direct service to large hotels in the Back Bay).

Even more, the Logan Taxi Twitter feed often includes this kind of Tweet:
By 10:00 most evenings, someone at Logan knows how many late flights are coming in. So, conceivably, the bus driver could be held on duty to make extra trips in the cases of delays. Massport, which already helps to subsidize the fares for the Silver Line, could shoulder the rather minimal cost of the extra trips. And passengers arriving at midnight would no longer have to face an hour-long wait for a cab, when there are many more options across the harbor.

The market has never provided enough cabs at Logan when they are needed, and at certain times of day, lines of cabs are the rule, not the exception. Assuming the market will take care of this has never worked, and it is unlikely that it ever will. If Massport worked with the MBTA, however, it could pilot a project to move people downtown and create a secondary taxi queue there, where drivers would be much more willing to go for a fare, because even if the demand had dried up, they wouldn't be out the tunnel tolls, mileage and time to show up at the airport.

Thursday, October 17, 2019

The next 10 miles of tunnel in Boston

In the past 30 years, Boston has been a leader (at least in the US) in building tunnels. The Big Dig, which removed the eyesore Central Artery from the center of the city and doubled highway capacity to the East Boston and the airport (which likely has something to do with the making Logan Airport one of the fastest-growing in the country), was one of the largest subterranean endeavors in the country's history. (If you really want to see tunnels, though, head to Europe or Japan. But I digress.)

In that time, however, the region has not built any new high-capacity, subterranean transit infrastructure aside from relocating the Green Line at North Station, which didn't add any connectivity or capacity (and it was part of the Big Dig, anyway). The Silver Line is not high capacity by any stretch of the imagination (although if it were converted to light rail, it could be much higher). Even the Green Line Extension, the first new line in decades, is being built entirely at- or above-grade.

Our competitor cities, even those in the US, are not standing still. While American cities are notoriously poor at building subways with any sort of cost controls, most every other city in the country with any sort of transit system has built some amount of underground rail infrastructure. Why do I focus on going underground? Because it's the only way to run high-capacity transportation through a dense portion of a city. Without it, we are stuck trying to push more and more people through the infrastructure we already have: our overcrowded subways and narrow streets. We can do this, to a point. But at some juncture, we need to think bigger.

Here are what other cities have been doing since the last new subway station opened in Boston (either in 1985, when Alewife opened, or 1987, when the Southwest Corridor replaced the elevated Orange Line), from west to east (approximately, and if I missed anyone, let me know):


  • Los Angeles: The entire Metro Rail system has opened, with 18.5 miles of tunnels. With in the next decade, the amount of tunnel will nearly double as the system expands dramatically.
  • San Francisco: The BART system was mostly complete by the 1980s, including the tunnels. Since then several miles of tunnel opened in South City and San Bruno with the Millbrae/SFO extension, and several more are planned as the line is built (expensively) through San Jose. Muni is building a new tunnel diagonally across San Francisco for light rail service. At some point, Caltrain, which is currently being electrified, may be extended to the Transbay Terminal.
  • Portland: While the MAX light rail system is mostly at- or above-grade, the three-mile Robertson Tunnel runs through a major ridge west of downtown.
  • Seattle originally opened its mile-long bus tunnel in 1989. It has since converted it for light rail traffic, extended the light rail south (with a mile of tunnel through Beacon Hill), north (in a deep bore tunnel) and will continue with northward expansion as part of a major infrastructure plan which involves building more than 100 miles of high-capacity light rail by 2041.
  • The middle of the country has not seen much in the way of tunneling. Denver's system is entirely at-grade, while Dallas has one subway station. Saint Louis has about a mile of tunnel under downtown and shorter tunnels elsewhere. Minneapolis built a mile-long tunnel under its airport. Pittsburgh built a mile-long tunnel under the Allegheny River, and Chicago built about a mile of tunnel connecting the State Subway to the Dan Ryan Branch, allowing routes to be better optimized. Buffalo's light rail, which runs below grade outside the city, was completed in 1986 but hasn't been extended since.
  • While much of the DC Metro system was completed by the mid-1980s, the last bits of tunneling weren't completed until 1999. Baltimore's subway was extended by a mile and a half in 1995.
  • New York hasn't built much since 1940, but has still managed the Second Avenue Subway, the F Train under Roosevelt Island and East Side Access (the same tunnel for part of the route), the 7 Train extension and the E train to Jamaica.
  • Which leaves Atlanta and Philadelphia. In Atlanta, MARTA's tunnels were completed in the late 1970s and early 1980s. Philly finished connecting its regional rail system in 1982. Much like Boston, these cities haven't made large investments in transit since (although MARTA has been extended as planned, mostly above-grade).

So, why Boston? Why now? Because there are several short stretches which could dramatically enhance the network, and the overall capacity of the network needs to be expanded. The last increase to the system's capacity was made in the early 1900s: since then, lines have been relocated, but not expanded. This doesn't go into the need for wider-scale regional connectivity or faster, more efficient surface transit (both are important, but cover a much broader scale). It instead focuses on how a few miles of tunnels could transform transit capacity in the city. Much like, for better or for worse, the Big Dig did. It's a very blue-sky approach and assumes a reasonably large investment (the state does have a billion dollar surplus), but each project is technically feasible and in most cases encompass projects which have been proposed at some point in the city's history (albeit in some cases, a long time ago).

They are presented in approximate order of length (shortest to longest) and feasibility.

1. The Red-Blue connector (0.25 miles)

The Red-Blue connector would require about 1300 feet of new tunnel. It's a good time for it: Cambridge Street above it is badly in need of a redesign, and MGH, next door, is planning adjacent construction. The MBTA is finally going to give it a fair shake, and it will hopefully see the light of day in the next few years.

But why is it important? Because it improves connectivity while at the same time reducing demand on the busiest part of the core of the system. It's a win-win, for a very small investment, and should be feasible to build with minimal disruption to the rest of the system.

2. The Silver Line Phase III, but with rails (0.5 miles)

This connection has flown more under the radar screen. With the growth of the Seaport, the Silver Line buses are overburdened, and there is no good way to get to it from the Orange or Green lines without multiple transfers. The Silver Line and Central Artery were designed to include the Silver Line Phase III portion of the project, which would have run east from South Station to Boylston, and then made an asinine loop to run south to a portal somewhere near Tufts Medical Center station (they couldn't use the old Green Line tunnel because, paradoxically, smaller buses require larger tunnels: louder now for those in the back or at Park Plaza, because buses don't belong in tunnels). And it would have run buses, which, as we see today, have no place in tunnels with stops and have low speed and low capacity.

This idea leverages a third piece of infrastructure, and one much older: the never-used provisions for a branch of what is now the Green Line from east of Arlington to a terminal at Post Office Square. Instead of going to Post Office Square, this would extend east along the SL III plans to South Station, then through the Piers Transitway (a.k.a, the current Silver Line, which was designed to be converted to light rail, providing faster and higher-capacity service) and on to Silver Line Way, where it could be extended at-grade to the Convention Center, Seaport or elsewhere, maybe even down Track 61. No, Track 61 as a DMU shuttle just doesn't work. This would mean a one-seat ride from Copley to the Seaport in 8 minutes, as opposed to two transfers and 20 minutes today.

I'll defer to Vanshnookenragen for some detailed graphics about how this would work, and some other good thoughts on the Green Line.

Two tunnels down and we haven't even dug a full mile.

3. Grand Junction (1.25 miles)

Now we get a bit bigger.

The Grand Junction Railroad has never carried a revenue passenger in its existence, which goes back to 1846. Until recently, the right-of-way once ran through a series of industrial lots and rail yards with little potential to carry paying customers. Now? It runs from North Station and passes Cambridge Crossing, runs through the heart of Kendall Square, and then on to Allston. Kendall has some of the highest-priced real estate on the face of the earth, and is growing by leaps and bounds, despite no direct highway access, which forces car traffic onto narrow, congested streets. It's accessible from the Red Line, and has reasonable connections to some of the rest of the transportation system, but from the north and west, transit is not time-competitive with driving, so, people drive.

Cambridge Crossing promises more demand, as does the eventual replacement of the interchange and rail yard in Allston. This provides opportunity as well: for the construction in Allston to take place, the Grand Junction will be shut down for a period of several years. In 10 years, the Grand Junction could connect Allston (millions of square feet of new development adjacent to Harvard and BU's campuses, as well as a transfer from the main east-west rail corridor in the state) to Kendall Square to North Station, with additional stops in Cambridgeport, East Cambridge and Cambridge Crossing (where the line passes only about 600 feet from the future Lechmere Station, which would provide a transit connection from the Green Line extension to Kendall Square).

This looks a lot like where you would want a frequent, high-capacity transit line, which would increase regional transit ridership (satisfying latent demand by providing connections which do not exist today) and take existing transfers out of the core of the system. What do I mean by this? Take the example of Boston Landing station. Before that station opened, there were no good options to use transit from Allston to Downtown Boston: The 86 or 66 bus to Harvard and the Red Line, the 64 bus to Central and then the Red Line, or the 57 bus to Kenmore and then the Green Line. Since it's opened, ridership has far exceeded expectations. Why? Because there's now an option to go from Allston to South Station in 14 minutes instead of 40. Some of this traffic comes from people who used to cram onto the 57 or 64 buses, and others take transit instead of driving.

The Grand Junction allows a similar time savings for travel to Kendall Square, except expands the benefit to everyone coming west of Boston. A trip from Boston Landing to Kendall today involves a 35 minute ride on the 64 bus, or taking a train to South Station and then the Red Line out; without the Grand Junction, traveling between West Station and Kendall will have a similar travel time, all for a trip which will cover, as the crow flies, little more than a mile. The Grand Junction is a straight line between the Worcester Line and Kendall Square, and cuts 20 minutes from the transit commute for every current or prospective passenger going to Kendall from west of Boston. The issue is that the Grand Junction runs across four heavily-trafficked city streets in Cambridge, and providing safe passage for even moderate operating speeds or frequency would be exceedingly difficult. Unless, of course, the line were put underground.

There are two main obstacles to tunneling the Grand Junction, but one major opportunity. The first obstacle is that it can't be a simple, shallow cut-and-cover trench, because in addition to utilities (which are present in most subway projects) the line would have to cross under the Red Line at Main Street. This would mean tunneling down below the grade of the Red Line, with the bottom of the tunnel likely reaching down 40 or 50 feet. Insurmountable? Given how many buildings in Kendall Square have recently been built with footings and basements at least that deep, no. Difficult? Yes.

The second obstacle is the land ownership. While the state has an easement across the corridor in perpetuity, it does not actually own much of it. When the Penn Central was looking to raise cash in the late 1960s and early 1970s, it sold off portions of its railroad to whoever would buy. In the case of much of the Grand Junction, the buyer was MIT. The wide corridor allows MIT to manage deliveries to its buildings and utilities under the surface, with a transportation easement on the surface for the rail line. While MIT has acquiesced to move the Grand Junction Path forward, digging a deep tunnel would be more difficult.

The opportunity, however, is that because of the Allston project, the corridor will see no rail service for a period of several years. Unlike something like the Green Line extension, where much of the cost of the project stems from rebuilding the corridor while maintaining active Commuter Rail service, the Grand Junction corridor would be a blank slate. It's much easier to dig a hole when you don't have to worry about what is going on above it. Roads could be shifted (shoo-flied) to allow for construction to take place (like how Harvard shifted Western Avenue in Allston for construction of an adjacent building). Work wouldn't have to be relegated to evenings and weekends to maintain weekday train service. Given the depth of the Red Line, MIT's utilities between Main Street and Mass Ave could be put into a newly-built conduit above the Grand Junction, allowing far easier access than the current procedure of digging around an active rail line and holes in the middle of Mass Ave. Cut-and-cover projects can be very expensive under city streets or other active alignments. But digging what amounts to little more than a mile-long basement shouldn't be impossible.

The Main Street is more difficult, but a concept would require closing Main Street (or shifting it), uncapping the Red Line, and digging down on both sides of the tracks while maintaining service. Once the pits on both sides were at the eventual depth of the Grand Junction passing underneath, the Red Line could be shut down for a week (perhaps the very low-ridership Christmas-to-New Years week) and a prefabricated concrete box could be assembled off-site and lowered into place, with service restored on the upper portion for the Red Line and, eventually, for the Grand Junction below. MassDOT is good at installing bridges in a weekend. This is essentially the same thing: the bridge takes the Red Line over the Grand Junction.

A few more concepts:
  • A Grand Junction station could be built between Main Street and Mass Ave, likely where MIT currently has a small, outdated building (Building 44) and an outdated parking garage (N4). North of this is a long-disused MIT property. Combined, these properties create an almost-perfect arrow shape, and comprise nearly 5 acres of developable land. A location atop a transit station could help the City leverage financial support for transit infrastructure in exchange for additional development rights.
  • On the north edge of the arrow property, an infill Red Line station could be built at Technology Square, filling a mile-long gap between the Red Line stations at Kendall and Central. This would provide better walking access not only to Tech Square, but also to other nearby developments, including NIBR, University Park and nearby residential districts, as well as a good transfer through the arrow property between the Grand Junction and Red Line. Given the rate of development in the corridor, a new transit station would help to relieve some of the crowding at the two existing stations.
  • Construction of a tunnel would allow a widening of the curve radius the Grand Junction currently uses between Main Street and Broadway. This would involve digging up much of the corridor there, but with the railroad already below the Red Line, it would provide the potential to add several hundred below-grade parking spaces below the street and above the rail line, which could be leveraged to allow nearby developers to build new buildings with less parking, or, perhaps, none at all. (In Delft, Netherlands, below-grade parking was integrated into a project burying a rail line.)
  • The tunnel would ascend to just below grade at Cambridge Street, and then rise east of there, tying in to the Fitchburg Line near McGrath Highway. This would probably require that Gore/Medford Street was raised several feet to accommodate the railroad grade.
  • This obviously would require electrification of at least this portion of the Grand Junction railroad, as well as the completion of additional track accessing North Station, which is planned
Here is a conceptual section (not to scale!) of a Grand Junction tunnel (looking from Kendall/MIT towards Central/Harvard):



Once the Grand Junction is rebuilt as part of the Allston project, demand for service will likely render this opportunity to shut the line down moot, so it would have to happen within the next decade. Given the opportunity to build a new transit line in an unused corridor, it should.

That's two miles. Total.

4. Grove Hall-to-Dudley Subway (2 miles)

The first three projects look at core capacity, delivering workers to jobs, and moving people out of transfers in the center of the system. This next one doesn't. If some cars which currently run to Park Street were instead split off to the Seaport, there would be more capacity at Park Street itself. Since the section of subway from Park Street to Boylston is four tracks, and the two extending south through the disused Pleasant Street Incline are grade separated, trains could be run in to the subway from the south, allowing service from Dudley Square to bypass the traffic and narrow streets downtown (because this is what the subway was designed for when it was built in … 1897). In other words, there's plenty of capacity at Park Street, as long as it doesn't all turn west at Boylston.

Why wasn't the subway ever extended south from the Pleasant Portal? Probably because the railroad was in the way and already below grade. To extend the subway would require not just digging a tunnel, but digging it deeper: something that didn't happen for decades anywhere in the system. By and large, other than crossing under each other, Boston's original subways hewed close to the surface.

By 1914, what is now the Green Line subway was extended to just east of Kenmore Square, and only in 1932 did the subway cross under the railroad, first at Beacon Street and then at Huntington Avenue in 1941. (The Turnpike doesn't make this crossing any easier.) The southern branch from Boylston was never extended under the wider New Haven and Boston and Albany right-of-way. But even the few existing, unused blocks of subway between Boylston and the portal would provide a major advantage: allowing service from the Washington Street corridor to bypass downtown traffic and extend north through the city. There is relatively little congestion south of there, and ample opportunity to run transit in a right-of-way on Washington Street: that's where the Silver Line has lanes, even if it doesn't need them. The Pleasant Portal could be reopened, and the line extended diagonally on the original route of the now-obliterated Pleasant Street across the land occupied by the 1970s-era Josiah Quincy School (which will likely need refurbishment or replacement at some point), and then down Washington Street.

Most of the rest of the corridor south through Roxbury to Mattapan on Washington Street and Blue Hill Avenue is wide enough that a modern light rail system could be put into place (think the Green Line, except completely different). Level boarding, prepaid fares, signal priority. The exceptions are two stretches, one through Dudley Square, and a second under Warren Street north of Grove Hall. Could surface transit run through these sections? Certainly, but it would be relatively slow, owing to narrow street widths on Warren Street and Washington Street and congestion at Dudley. North of Dudley, it would make sense to extend a tunnel past Melnea Cass, to avoid traffic-related impacts to transit. This tunnel would be more difficult to build than the Grand Junction and longer as well, and would probably require a tunnel boring machine and two stations (at Dudley and Malcolm X, which would probably be the first transit station named after Malcolm X). 

Still, this tunnel would leverage several physical assets already in place. It would allow transit from the center spine of Boston to get downtown without sitting in downtown traffic, like the Silver Line does today, and to potentially extend north along the route of the Green Line extension. It would provide the promised replacement for the Orange Line that was moved a generation ago. And it would use Blue Hill Avenue, perhaps the widest roadway of any length in the region, to transport far more people than the 28 bus can.

Four miles down. The next two are bigger bores, bigger miles, and bigger impact.

5. Seaport-Logan Regional Rail (North-South Rail Link, Part 1, 3.5 miles from South Station to Wood Island)
6. North-South Rail Link, Part 2 (2.5 miles from south of South Station to north of North Station)

The last two tunnels are the North-South Rail Link, about which my thinking about has evolved over time (for instance, with the redevelopment of North Station, I'm not so sure you'd want to skip it). Why split it in two? Because I think that the NSRL actually makes sense as two mostly-separate tunnels converging at South Station.

The first of these would of these would be a tunnel from South Station to East Boston, which was proposed as early as 1911 (!). Today, trains from Newburyport and Rockport (the Eastern Route) follow a straight line down the coast towards Boston until they get to Bell Circle, but then bend away to the north through Chelsea to loop around to North Station. The railroad originally operated towards a ferry in East Boston, but was rerouted to serve the city proper. Most iterations of the NSRL maintain this routing. 

There are two missed opportunities doing so. The first is the ability to halve the number of tracks in the main NSRL tunnel. With trains headed out on all four lines north of the city, a two-track tunnel would be unlikely to accommodate all of the service from the north (and certainly not all from the south), requiring the maintenance of surface stations and additional track on both ends of the system. Splitting off the Eastern Route would reduce demand on the main trunk enough that it could probably get by with two tracks in perpetuity. In other words, the NSRL would still have four tracks, they just wouldn't be all together.

The second missed opportunity would be better service to Logan Airport. Transit service to Logan Airport today is pitiful and traffic at a breaking point, so despite sitting just three miles from Downtown Boston, it can take the better part of an hour to get from Logan to the city. Getting anywhere besides areas served by the Red or Blue lines requires multiple transfers, which are unattractive for all but the most budget-minded travelers, and adding time to airport staff. 

Yet imagine the following: half of the trains from the lines south of the city, including express trains from Providence and Worcester, would stop at Back Bay, South Station, a stop in the Seaport and then a central station at the airport. South Station to Logan would take 6 minutes, Back Bay to Logan 10, and Providence and Worcester would, assuming the necessary improvements to the rail network, have less-than-one-hour, door-to-door service. Some trains would terminate at an airport station (which could be built with enough tracks to allow trains to terminate and layover), and others would continue through a short tunnel under airport property and East Boston to the original route of the Eastern Railroad along Route 1A and north to Lynn, Salem and beyond, which would see faster trips both to the airport and Downtown Boston. The currently-used cutoff could provide continued service from the North Shore, or be used as a shuttle service from Revere through Everett to Sullivan Square, or even connecting to the Grand Junction. This would mimic the transit access to many large airports in Europe, like Amsterdam, Frankfurt, Zurich, Geneva, Oslo and London, where the airports are connected not only to the subway, but to larger, regional rail systems. 

Constructing such a tunnel would be difficult, but we built the Big Dig in roughly the same alignment, and constructing a parallel tunnel on the floor of the Harbor would certainly be feasible (in fact, some of the base geologic work may already be done). An airport station would be required, and expensive, but could be integrated to a major rehabilitation of the airport's ground transportation network, which can barely cope with current traffic. This tunnel would stretch 3.5 miles—making it the longest of the tunnels proposed—yet most would be constructed under the Harbor, under open areas at the airport, or transportation corridors in East Boston. That should be easier than going straight through Downtown Boston. Although that's a pretty low bar.

The final tunnel, about which I won't go into further detail here, would be the classic South Station-to-North Station NSRL, only with the demand from the Eastern Route removed, and two tracks through the center of the city. All trains would connect at South Station, allowing transfers, and allowing the entire regional rail network to get to the airport with at most a single transfer. South Station is only a mile and a half from North Station and the Airport. A good transportation network would provide a simple trip to both.

Grand total: 6 tunnels, 10 miles and a bridge (so to speak) to the next century.



There's plenty missing, of course. Vanshnook suggests a Green Line tunnel from Allston to Harvard and Northeastern to Brookline Village, for instance. Wentworth students have imagined a Blue Line link from Government Center to Kenmore. But for my money if I was given 10 miles of tunnel, this is how I would spend it.

Thursday, August 29, 2019

It's Time to Radically Rethink Memorial Drive in Cambridge

Memorial Drive in Cambridge—a pleasure roadway and a park—is actually a death trap. The wide, straight roadway encourages cars to speed, and speed they do, running over a pedestrian several times per year and killing people far too often. The roadway hosts no commercial vehicles, and the eastbound lanes serve only a couple of boating facilities between the BU and Longfellow bridges, yet the roadway—which was designed for low-speed horses and carriages—is built as if it were a highway, and any efforts to improve pedestrian safety have been stonewalled in the name of keeping traffic moving.

Except for a couple of traffic lights and poor-visibility sidewalks, traffic can proceed unimpeded from the BU Bridge to East Cambridge, on a straight, flat, mostly divided highway, where the 35 mph speed limit is honored in the breach. It's no fun to walk across and only slightly more fun to walk or bike along. Officially, it's a park, but it doesn't seem like one.

Memorial Drive is part of the Charles River Basin park and there is a 2002 master plan for the basin. Portions of this plan have been implemented, including the new paths along the Cambridge side of the river, but the roadways have not been touched. (Believe it or not, until the 1990s, parking was allowed on both barrels of Memorial Drive, so there was even more pavement on Mem Drive east and a line of cars along the river.) The plan proposes narrowing the road slightly and moving the eastbound barrel inland from the river, slightly increasing the width of the park along the river. It says that other options were considered, but not advanced further in to the plan. One of these would have eliminated the eastbound roadway entirely, channeling all traffic on to the combined westbound barrel. Apparently removing the roadway would be incongruous with the historic nature of the roadway:
While there is some flexibility in applying preservation criteria, the historic value of this cultural landscape would be entirely lost under this alternative.
I call shenanigans. I don't remember Frederick Law Olmsted planning for two lanes of 40 miles per hour automobile traffic in each direction, and parking. I think the DCR is afraid of reducing the number of lanes on the roadway. Rather than focusing on what the road looks like today, what if the DCR prioritized what would best serve as parkland for the public?

Instead of trying to rebuild the highway-like park (or is it a park-like highway) let's consider moving traffic to the westbound lanes. Use this roadway for two lanes of traffic, turning lanes at intersections, pedestrian refuges between the lanes to minimize crossing distances and some parking where needed (and charge for it if you can't figure out how to pay for the roadway changes). At the same and the eastbound lanes can be converted to parkland, increasing green space and allowing us to reclaim the dead space in between the current roadway. It might not match his parkway, but it would create a Cambridge esplanade. I think old Frederick Law would be proud.

There is an 80-foot-wide median between the two barrels of Memorial Drive today, but this is lost parkland, since it is nearly impossible to access and cut off from both MIT and the river, and who really wants to sit in a park in the middle of a highway anyway? If the roadway were consolidated, it the amount of useful parkland would go from 40 feet wide to 145 feet wide. On the MIT side, the portion of the parkland between the road and the sidewalk isn't even grass, but instead wood chips and mud, since it receives heavy pedestrian use, so the road could actually be pushed north there. This would provide enough room for one lane of traffic in each direction, left turn bays on and off of Memorial Drive where needed, and parking spaces elsewhere. By using part of this space, no trees would be impacted (which would be the case of the roadway were moved south).


But only one lane for cars in each direction? Yes! Memorial Drive in Cambridge carries about 36,000 vehicles per day. While this is high for a single lane in each direction, it is not without precedent, especially for a roadway with few intersections or interruptions. In fact, the DCR has a very similar stretch of roadway with a single lane in each direction which carries the same number of vehicles a few miles west: Nonantum Road, along the river in Brighton and Newton. Most notably, this roadway used to have four lanes but, according to the same master plan, was reduced to two in 2010, yet with turning lanes, traffic throughput has not decreased. The new design allowed room for an expanded bicycle/pedestrian path alongside as well.

These two roadway designs carry the same number of vehicles.

2007:

2018:

The 2002 master plan is dated, but it provides a blueprint for improving Memorial Drive. The DCR and MIT have started to implement some improvements, but these are small steps. It's time that Cambridge had an esplanade along the river, not a strip of parkland and a wide highway.

Friday, June 14, 2019

Don't double down on the mistakes of the past: Cabot Yard edition

The Red Line derailment didn't look too bad at first. The train stayed upright, there were no major injuries, and it appeared that the train would just have to be rerailed, the track repaired, and normal service would resume. The T did an excellent job setting up what skeleton service they could to bypass the site, providing rail service to Braintree and Ashmont without resorting to trying to put ten thousand people per hour on buses which would tie up half of the bus fleet (which is otherwise occupied at rush hour). It seemed the incident had happened in a relatively good location, one of the few where there was some redundancy, as passengers could just transfer from one side of the station to the other.

On Wednesday we found out just how bad it was. With the railcar finally removed (it is rumored that the reason the crane wasn't placed on the Columbia Road bridge as originally proposed was because DCR didn't know the maintenance level weight limit of the bridge and dropping the bridge on the Red Line would have been even worse) we saw what it hit. The little building next to the tracks housed the signal equipment for not only Columbia Junction—often dubbed Malfunction Junction, and that's when the signal system works!—but several miles of track in either direction. Now the 14 trains per hour normally scheduled across the line—which are barely enough to handle rush hour traffic—are reduced to four to six, for the foreseeable future. It turns out that this derailment didn't happen in a good location, but a bad one.

Signal systems are complex and bespoke, so a full replacement may take months or years to procure, if not longer. In 1996, when the Muddy River flooded into the Green Line, normal operations didn't resume for months, and fixes for the system itself took years, and $40 million in repairs. The T now closes the Fenway portal during heavy rain events every few years to prevent a repeat of that situation. However, the proximate cause—flooding from the Muddy River—was a bigger issue: a century ago, the river was relocated in to culverts below Park Drive, and with only so much space in the culverts, it would back up along the Riverway during heavy rains, overtop the levee, and, once the D Line was built in 1959, pour in to Kenmore (which had happened in 1962 as well). This was eventually fixed as part of a 20-year project spearheaded by the Army Corps of Engineers and multiple other agencies, and with the new drainage in place, future flooding of the MBTA is less likely. Instead of continuing with the same reactionary system—where floodgates and sandbags were required every few years, and if they didn't work, as occurred in 1996, the results would be catastrophic—we changed the larger ecosystem to one which would prevent the problem in the first place.

The Red Line derailment should serve as a similar wake-up call. Despite Governor Baker's repeated calls for no new revenue, simply fixing the system we have won't work. We—and I'm putting this in italics—can not continue to double down on the same system we have and expect different results. In the short term, this is going to require we invest in the system to make it more efficient and more resilient. In the long term, addressing wider problems will create the sort of system that will pay dividends when things like this week's derailment occur less frequently and, when they occur, have less impact.

A short history of Cabot Yard and Columbia (a.k.a. Malfunction) Junction

The Red Line was the last of Boston's subways to be built. The original segment operated between Harvard and Park and it was eventually extended, as the "Cambridge-Dorchester tunnel", to Ashmont. At first, the only yard facility was on the north end of the line at the Eliot Shops, a complex of yards and shops tucked between Harvard Square and the Charles River, which is home to the Kennedy School today. When the line was extended in the 1920s, it added another yard—Codman Yard—past Ashmont station. For the next 50 years, the line would operate quite simply: trains would pull out of a yard beyond the terminal, service the line, and then pull into the yard at the terminal. This is optimal: the line requires no mid-line switches, and every train coming in or out of service simply pulls in to the first stop.

The 1970s and 1980s changed that. In 1965, the T purchased the Old Colony right-of-way to build an extension to Quincy and Braintree. This was originally planned to be an independent, express line (which is why there is no Braintree station at Savin Hill or Neponset) which would terminate at South Station. Eventually, it was aligned to be part of the Red Line, which required a new junction where the lines split at Columbia Road.

More importantly, it needed somewhere to store and service the cars. The Eliot Shops were small, cramped, and sat on valuable land eyed by Harvard for years. The T gave the land to Harvard in 1966 but needed to find a new location for its yards. The Ashmont Branch was out: Codman Yard was surrounded by housing. Braintree didn't want a rail yard at the end of the line and blocked efforts for a yard there, so the T finally paid the Penn Central for the freight yards in South Boston to store Red Line cars. This was by no means their first choice: in order to access the line, trains would have to traverse nearly two miles of non-revenue track to get to JFK-UMass, and would then have to run the rest of the way back to Braintree to begin their inbound trips. (A small yard—called Caddigan, in keeping with an apparent rule that all Red Line facilities must begin with a hard C—exists past Braintree, but it can only store a few cars.)

This issue was exacerbated in the 1980s when the Red Line was lengthened once again. The line was extended from Harvard to Alewife, but was originally slated to go beyond. As late as 1977, the line was planned to Arlington Center (with an eventual extension) and the decision was made to curve the line past the Alewife station to aim towards Arlington, forgoing the ability to build a yard on then-vacant land just west of Alewife. The next year, the town decided it didn't want rail service, but the deed was done, and no terminal was available at the north end of the line, either. (This was related to me by Fred Salvucci, who had some choice words for Arlington and Cambridge about this. I've written about an idea to build a yard below Thorndike Field beyond Route 2 to mitigate the terminal issues at Alewife.)

So Cabot is it. It serves most of the trips for the Red Line and is the only maintenance facility. It sits less than a mile from Downtown and the Seaport on what is undoubtedly valuable land. (The nearby MacAllen Building and its neighbor have 279 condos; the two northernmost portions of Cabot are about three times as big.) And Cabot is the main reason that the location where the train derailed—Malfunction Junction—is as complex as it is. In fact, the switch where the train derailed has nothing to do with splitting apart the branches of the Red Line, but rather a switch for a "yard lead" allowing trains to return to Cabot. The entire complex is conceptually designed quite well: it creates a series of "flying junctions"—not just between the two branches, but also for trains between the Braintree line and Cabot (most Ashmont trains operate out of Codman so therefore don't require as frequent movement). This requires a series of complex switches and flyovers, but means that operationally no train ever has to cross another line.

Columbia Junction. North (towards Downtown Boston) is at the left. A snippet of a full MBTA track map (the best MBTA track map!) which can be found here.
But Columbia Junction, as built, is a known problem spot and frequent cause of delays, and this doesn't change the fact that Cabot is in the wrong geographic location for a rail yard. In Chicago, nearly every yard is at the end of the line, or close by (the last mid-route yard—Wilson—was decommissioned in the '90s in favor of a yard at Howard). New York, DC and San Francisco rely on yards mostly built on the outlying portions of the line. The T specializes in mid-route yards for the Orange and Blue lines (Wellington and Orient Heights), but both are located adjacent to the line, not miles away.

Thus, Cabot Yard has four major problems:
  • It connects to the wrong part of the line for a rail yard
  • It is not even close to said line
  • Where it connects to the line it requires a series of complex switches
  • It sits on otherwise valuable land, probably the most valuable land of any heavy rail yard (setting aside Commuter Rail yards downtown which, while in sensible locations operations-wise, sit on huge parcels of valuable land and which could be freed up with a North-South Rail Link, but that's the topic of another post entirely).
The T's plan? Rebuild Cabot Yard and Columbia Junction. The cost? At least $200 million for Cabot, and another $50 million or more for Malfunction Junction. The benefits? Negligible. Fixing the switches will help, but Cabot would still requires long non-revenue movements to get trains to the wrong part of the line to provide service and uses high-value land to store rail cars. It's cheaper in the short run than building a new facility, but doubles down on the same issues which require extraneous operations and needless complexity. Yet this is the Charle Baker "no new revenue" vision: keep investment minimal now, continue with the same system we have even when it clearly doesn't work, and somehow expect a different result. 

The solution, of course, would be to build a new yard facility somewhere further south along the Braintree branch of the Red Line. The question is: where?

The Braintree Split

I wrote last year about how the optimal location for bus garages is probably on state-owned land adjacent to highways, rather than next to transit stations as the T is proposing at Wellington and Riverside. No one wants a bus yard in their backyard, and building bus lots next to train stations instead of transit-oriented development is doubly wrongheaded. While rail yards are more location-constrained than bus yards (since they have to physically connect to the railroad) there is some potential to leverage the same sort of arrangement of land in Braintree for the Red Line.

If the Braintree branch were being built today, a logical location for a yard would be at what is currently the Marketplace at Braintree development. When the line was built, this was an active rail yard (a small portion still is a freight yard), and the Red Line was built on the "wrong side" of the tracks to access this parcel. Using it today would require not only nearly $100 million to buy the land and businesses, but nearly-impossible negotiations to somehow reimburse Braintree for that commercial tax base. The site south of the Braintree garage has less value (about $25 million) but is also on the "wrong side" (the Red Line is east of the Commuter Rail to allow access to what is now the Greenbush Line) and would require some sort of flyover or duck-under to gain access, while being slightly smaller than Cabot. Further south, there are some potential sites, but these would require longer lead tracks and have potential wetland impacts and NIMBY implications.

A map showing the locations of the sites mentioned above.
There is a site near Braintree, however, which would have no acquisition cost, since the state already owns it. It would have no impact on the tax base, since it has no assessed value. It will never be suitable for residential or commercial development, since it sits inside a highway interchange. It is, of course, the land within the Braintree Split. The land in the "infield" of the Braintree Split amounts to about 70 acres, which is nearly four times the size of Cabot Yard. The interchange is a "Directional-T" interchange, and designed so that at its center, three roads cross each other at the same point. The are, from lowest to highest, the mainline route from 93 north to 93 north, from Route 3 north to 93 south, and from 93 south to Route 3 south. This is important, because it would impact how a potential rail yard could be linked together.

None of the parcels bounded by the Braintree Split is as large as the entirety of the Cabot Yard (about 18 acres), although Cabot itself is split roughly evenly by the 4th Street bridge between the maintenance facility and the storage yard. Four of the sectors are roughly the same size, two are significantly smaller. Given the topographical constraints, it would be easiest to link together the 16 and 12 acre parcels. The map below shows the parcels within the Split, the size of each in acres, and, superimposed with dashed lines on the 16- and 12-acre parcels, the outlines of the Cabot shops facility and storage yard, respectively, with dashed lines.

Braintree Split parcels, with the Cabot shops and yard superimposed on the 16- and 12-acre parcels.
The Braintree Split is not as optimally located as, say, the site south of the Braintree station. It's a bit further from the Red Line, and not at the end of the line, so some deadhead movement would be required to reach the terminal. But it's considerably closer to both the end of the line in Braintree and to the line itself. The closest portion of the 12-acre parcel is only about 0.25 miles from the Red Line tracks, although there are some roadway ramps in between. (There are plenty of examples of rail yards interacting with highways, like the WMATA West Falls Church yard in Virginia, 98th, Rosemont and Des Plaines yards in Chicago,  and South Yard in Atlanta.

It is worth noting that Braintree Split isn't exactly flat. If you drive from 93 south to Route 3 south, you descend from an elevation of 180 feet down to 40 feet. Rail yards have to be flat (so, you know, unmanned trains don't roll away if their brakes fail), and rail grades, even for a rapid transit line, should be at most two or three percent. Given that the 12-acre parcel is lower than the 16-acre parcel, the two would have to be used for separate facilities, but there is no reason that the 12-acre parcel couldn't host a storage yard with shop facilities at the 16-acre parcel. In fact, the 12-acre site is better suited for a storage facility (since it is long and narrow) while the 16-acre site would have plenty of room for a maintenance facility and potentially additional storage tracks, which might be necessary if the Red Line were one day improved to offer service every three minutes.


This would require about 1400 feet of lead tracks from the Red Line to the storage yard, and no new land acquisition as all would be built on land already owned by the state. The yard lead would extend flat over the first set of ramps and Route 3 north (the Red Line climbs at about a 3% grade out of Quincy Adams to cross over the Old Colony Commuter Rail), and would then descend down to the level of Route 3 to pass over the northbound Burgin Parkway ramp and under the southbound one. There it would split in to two, with one set of tracks leading to a level storage facility and the other extending up to the maintenance facility further north. Access to the maintenance yard would be available from near the zipper lane facility just north of the split, although parking might be better provided on the side of the highway with a pedestrian bridge for workers to access the yard. If funds were available from nearby developers, these walkways could even allow a station to provide better access to nearby office buildings to provide a shuttle service from Quincy Adams or Braintree.

Simplifying Columbia Junction and Savin Hill

There are other knock-on effects to simplifying Columbia Junction and relocating Cabot Yard.

In addition to the Old Colony Commuter Rail line running through a single-track bottleneck south of JFK-UMass (which is part of the reason only a few extra trains can be run at rush hour), there is a bottleneck on I-93 there as well. In 2012, CTPS developed a concept to add HOV lanes to I-93 and a track to the Old Colony lines (thereby removing a single-track bottleneck) near Savin Hill by burying both the Old Colony and the Red Line for the better part of a mile. Yet this concept would likely rival the Allston I-90 project in complexity and cost.

With South Coast rail now being (wrongly, in my opinion) pushed down the Old Colony Line, the FMCB has considered a similar plan. Yet this is based on the false premise that four tracks need to be provided to JFK/UMass, which is mostly required to allow access in and out of Cabot Yard from the Braintree Branch. Without the need to access Cabot Yard via a flying junction, there is no need for four tracks through Savin Hill: by combining the two Red Line branches south of Savin Hill, one of the existing Red Line tracks could be used for Commuter Rail through the Savin Hill bottleneck with only some minor modifications, at least relative to the state's incoherent plan. In addition, by replacing Cabot Yard with a facility in Braintree, the entirety of "Malfunction Junction" could be replaced by two switches, one to split the southbound main line in to two branches, and another to combine the two northbound tracks together.

The sketches below show the current configuration of the railroads adjacent to Savin Hill, and a proposed concept. The proposed concept would have outbound trains stop at Savin Hill, but inbound trains on the Braintree Branch (which has less capacity) would bypass Savin Hill and merge in past the station (as they do today), although it could certainly be realigned to allow all trains to serve Savin Hill. North of this junction, the Red Line would operate as a simple, two-track railroad through to Andrew and on to Downtown and Alewife. Inbound passengers at JFK/UMass would no longer have to play platform roulette, or stand on the overpass and wait for the next train, as all service would take place on a single platform.

Current track layout.

Proposed track layout showing the combination of the Red Line branches moved further south.
The Cabot Yard leads and Track 61

The tracks from JFK/UMass to Cabot would not have to go unused, however. I pointed out several years ago that Track 61 could reasonably be connected to Andrew Station to provide a shuttle from JFK/UMass to the BCEC and Seaport. With the Cabot yard leads freed up, such a shuttle could instead run from JFK/UMass to the BCEC, providing a connection from Dorchester and the South Shore to the Seaport without relying on the overburdened Silver Line. There should be enough room for two light rail tracks from JFK/UMass to the Seaport (with a single-track terminal at JFK, much like the Braintree branch of the Red Line is being operated after the derailment) with the other Red Line track given over to the Commuter Rail. This would provide a useful link using the otherwise-excess right-of-way.

Cabot Yard as midday layover for Commuter Rail

While Cabot Yard is poorly-located as a Red Line facility, it is in the right place for midday Commuter Rail storage. This page is on the record saying that the best way to reduce the need for midday storage is to just run more trains, but peaks will be peaks, and having somewhere near a terminal to store trains will be important until we build the North South Rail Link (in which case trains will be able to run through the tunnel to outlying yards, freeing up land near the terminals). Today, the Commuter Rail system uses yards at Southampton (near Cabot) and Readville (at the end of the Fairmount Line, so not near Cabot, or really anything) for midday train storage.

Yet to run more trains, the agency needs more storage, so it is looking at sites in Allston and Widett Circle, despite the expense of building in these locations and their desirability as development sites. (As a participant in the planning process for Allston, the supposed need for storage drives many undesirable and expensive portions of that project.) If Cabot Yard was vacated by the Red Line, it would make a fine facility for midday storage: it's very close to South Station and, with a rail yard on one side and bus yard on the other, a less-desirable development site. The portion of the facility between the Haul Road and 4th Street is more than double the size of Readville, and could thus replace Readville entirely while providing enough additional capacity to obviate the need for new construction in Allston or at Widett Circle.

Conclusion

As usual, actions taken in one location decades in the past cascade through the entire transportation network. NIMBYs in the 1960s pushed the T to build Cabot Yard, even if it was nowhere near the Red Line itself. A changing economy means that the land it occupies, which was little more than a post-industrial wasteland in the 1970s, is now worth hundreds of millions of dollars. The Braintree Split, built in the 1950s, provides enough room for a rail yard in its median. Malfunction—er, Columbia—Junction has always been a solution looking for a problem. By thinking pretty far outside the box, we could correct many of the mistakes of the 1970s. But it involves making an investment in infrastructure beyond just fixing what we have.

The current administration, it seems, is willing to double down on the mistakes which got us in to this mess. When the Muddy River flooded in to the Green Line, we didn't just build a storm barrier and hope that it would work. We looked upstream for the cause, and rebuilt the Muddy River to keep it from overflowing in the first place. While the reactive solution might seem cheaper today, in the long run, unless we take proactive, decisive action, we'll pay for the mistakes again and again.