Saturday, December 21, 2013

Take the (train/bus/car) to the ballgame

When the whole melee about Cobb County Braves broke last month it got me thinking about a long-thought project of mine: calculating travel mode share to baseball parks. Ballparks see the most visits of any sport (a multipurpose arena with hockey and basketball only has as many home games as a baseball team, with half the capacity), and ballparks are often (although not in the case of the Braves) seen as means to revitalize downtown areas.

So, I created a chart of each stadium, and how far it was from various transit modes. And then I mapped it out:

Green shows transit options within ¼ mile, or a five minute walk. Yellow is within ½ mile (10 minutes) and red within a mile (20 minutes). Note that bus stops more than half a mile form the stadium are not shown. Here is a Venn-ish diagram of the same data:

A few notes:
  • 28 ballparks lie within half a mile of some transit option. (The exceptions: Arlington, Texas—which doesn't even have transit within the city limits!—and Kansas City, have bus stops less than a mile away.)
  • 3 cities have no rail transit but do have bus service. Miller Park, built with huge parking lots for tailgaiting Wisconsinites, is the only one of these ballparks more than a quarter mile from the nearest bus stop.
  • Boston, Baltimore and Toronto have all four transit options within half a mile of the stadium. (In Boston, the Green Line, despite carrying more passengers than several subway systems, is classified as light rail; the Orange Line, half a mile away, is the heavy rail option.)
  • Denver is opening a multi-modal station near the current ballpark, this reflects the projected opening next year.
  • The Braves new ballpark will be nearly a mile from the nearest bus stop, putting it in the company of Texas and Kansas City.
  • Historically, ballparks were often further from the city center, and served mainly by streetcars, even in cities with subways. Braves Field, Shibe Park, Ebbets Field and the Polo Grounds were all closer to streetcars than to subways. (And note that Fenway Park, Yankee Stadium, and both ballparks in Chicago are not in the downtown core.)

Monday, December 9, 2013

Come see the StreetTalk 10in1 Wednesday!

This Wednesday, in beautiful Central Square, there is a thing called the 10-in-1 StreetTalk. The folks at LivableStreets solicit 10 presentations of no more than 7 minutes, and gather people to hear them.

And guess who's presenting? This guy. And guess what I'm presenting about? This. Of course.

Find out more information here. And come for the other presentations!

Wednesday, December 4, 2013

MBTA still won't provide real all-night transit

The MBTA recently announced a pilot program to extend service hours on Friday and Saturday nights. This is a great step for the T, which hasn't had subway service after midnight in over 50 years. While it does reduce the amount of time the T will have to inspect and fix its aging infrastructure, the other five nights will still have time for track work, while serving the busiest nights for late-night ridership. This is all good.

What Boston will still lack is an actual late-night transit system.

In every other major transit city in the country (More than 25% mode share: NY, Chicago, SF, DC, Philly or more than 1m daily ridership: LA), there is an option for getting around between midnight and 5 a.m. Not just on weekends. Not just until 3. (DC is a slight exception, some overnight bus routes shut down for 30 to 120 minutes around 3:00; but some routes, like the 70, have no more than an hour gap in service.) Service may only come every hour, and it may be a bus instead of a train, but if you need to get somewhere at 2 a.m., you might be able to take a bus there. This is not the case in Boston, and even with added Friday and Saturday night service, it still won't be. Several smaller cities operate all-night transit systems as well.

Late night transit service is going to cost money, but depending on how it is structured it can serve two economic purposes:

  1. "Cosmetic" late-night service (such as what is being proposed by the T) makes Boston more competitive compared to other cities. Apparently, workers are more likely to want to live in Boston because if they work late on a Friday night and have a couple of drinks, they don't have to worry about the train shutting down an hour before last call. (This Globe article makes that point.) By calling it "cosmetic" I don't mean to make light of this, as moving Boston towards being more of a 24-hour city is a laudable goal, and pushing train service later on weekends is certainly a good move. DC operates similarly; the Metro there stays open until 3 on weekends while shutting down around midnight most nights, but they manage to run a few popular bus lines all night, or close to it. And, yes, the workers behind the nightlife will be able to finish their shifts and catch the last train instead of ponying up for a taxicab or driving.
  2. Full late-night service, however, serves a much wider economic purpose: it provides access to employment centers which would otherwise be inaccessible during certain hours. This page has argued this point in the past, making the case that the MBTA or Massport should fund and provide at least a low level of 24-hour service to the airport, where many shifts begin or end between midnight and 5 a.m. But there are other overnight workers too. Overnight service on major transit routes, even if it were only every hour, would provide job access, especially for low-income service workers who spend an inordinate portion of their income for driving and (at the airport especially) parking costs.
How does the rest of the country do it? Because I love charts, here are some charts. I'll explain more below:

Obviously, New York skews this whole chart. It has more than four times the transit ridership of any other city, and 138 all-night routes (18 subway lines, the PATH, the Staten Island RR, 16 bus routes in Manhattan, 29 in Brooklyn, 47 in Queens, 17 in the Bronx and 8 on Staten Island). Let's remove New York. Here's the same chart, sorted by transit ridership, with the number of overnight routes highlighted:

Notice something conspicuously absent in the chart for Boston? It's the only city with high transit ridership without overnight service. The next largest? Atlanta, which is not known for it's transit friendliness (i.e. we're not moving the Red Sox to Danvers) and has a third the daily ridership of the MBTA. And several smaller cities have pretty comprehensive late-night transit systems. Las Vegas makes sense; the city basically operates 24/7. And last call in Miami is 5 a.m. But Cleveland and Baltimore? They're not what we think of as 24-hour cities. Yet they provide overnight transportation.

So the question is: is Boston going to put a cosmetic "hey look the trains run late filled with drunk people" band-aid on the situation? Or are we going to actually have a discussion of how to provide 24-hour transportation for citizens, and to jobs?

(There's a longer history of cuts to overnight service. Many cities, including Boston, had owl service in the 40s and 50s. In quite a few cases it survived longer. For example, Portland Oregon cut overnight service in 1986, and Minneapolis had a more extensive network until 1998.)

(By the way, if anyone knows of any other cities with overnight service—other than Newark which runs the 62 all night to EWR, I know about it—let me know. I was surprised that I could find neither a list of transit agencies by overall ridership nor a list of cities with overnight bus service. If anyone wants to help fill out these lists, I'm all ears.)

Thursday, November 21, 2013

The new Harvard Bridge bike lane, animated-GIF style

The state, thanks in part to LivableStreets' tireless advocacy, finally repaved the Harvard (/Mass Ave/Smoot) Bridge, and restriped the bike lane to a full five foot width. Previously it had narrowed to 20 inches at the foot of the bridge, which was substandard and dangerous. Now, it's 5 feet wide, making it much easier to navigate on bicycle, and keeping the cars in the middle of the road. Here, in two pictures is the progress that was made:

In the animated GIF (on the right; give it five seconds), I didn't perfectly take the picture from the same angle, so it's not layered right on top (the "before" picture was taken the summer doing recon from a BS traffic stop). Note the location of the drain, and that while the bike in the "before" is closer to the drain, he's outside the bike lane, while in the "after" the cyclist is further from the drain, but comfortably in the bike lane. Yes, at the edge of the frame is a Street Ambassador, the work of whom led to this better bridge. So that's cool, too.

Also, the pictures were taken at 1:30 (standard time, November) for the after and 6:30 (daylight time, July) for the before, and the shadows are the same length.

Wednesday, November 20, 2013

Allston-Brighton toll straightening shouldn't ignore Soldiers Field Road

Massachusetts has taken on a surprisingly progressive role in transportation policy in recent years, with the transportation secretary publicly stating that "we will build no more superhighways" and setting explicit goals for a shift away from single-occupancy driving. As part of this fix-what-we-have policy, the state is planning to convert the whole of the antiquated tolling system to open-road tolling, eliminating toll boots and charging vehicles based on transponders and license plates. This is a good step forward as it will not only reduce congestion at toll booths but also reduce the amount of land required by the serpentine ramps and plazas needing at Turnpike entrances and exits. While rural interchanges won't be changed, it give the opportunity to rework a lot of urban land previously occupied by redundant roadways.

Nowhere is this more of an issue than at the Allston tolls in Boston. Here, the main trunk of the Turnpike loops around a now-disused rail yard, and a convoluted set of ramps feed on and off of it with four separate toll plazas. The state has announced a $260 million plan to straighten this interchange, which contains dozens of bridge spans in need of replacement. An early conceptual design has been announced that reduces the amount of land required and simplifies the roadways. While this is a good start, it ignores the space just beyond the interchange, namely, the confusing and dangerous interchange with Soldiers Field Road which is congested, a major impediment to bicyclists and pedestrians and which darkens a stretch of the Charles River with highway ramps and traffic jams.

Typical traffic.
The Turnpike-Cambridge/River Street-Soldiers Field-Western Avenue interchange is a royal mess. It is so confusing that the state long ago stopped maintaining lane markings, and today it is a free-for-all as vehicles jockey for position as ramps funnel in to each other at a series of lights. For bicyclists and pedestrians? It's a nightmare. Coming east on Cambridge Street is nearly impossible through the traffic chaos, and even crossing Western Avenue and Cambridge/River Street on the Paul Dudley White Bike Path is difficult, without a specific bike/ped cycle, crosswalks, curb cuts or even, at the southern bridge, a walk light!

A bit of a radical idea here that I'm proposing would be to move Soldiers Field Road away from the River. From Boston to Watertown, nearly the entirety of the Charles River is lined by highways. Yes, there is a bike path squeezed in between the riverbank and the roadway, but it is clear that cars are given the priority—we've turned our back on the river. The bike path is narrow, and when it intersects roadways crossing amidst the turning vehicles, it is perilous. It is a poor excuse for bicycle infrastructure, yet it is quite heavily used. Added to this, Soldiers Field Road doesn't even follow a straight line but hugs the riverbank, adding distance (and pollution) for motor vehicles.

Here, then, is a conceptual plan to both improve the Turnpike interchange and the connection between the Turnpike, Soldiers Field Road, Western Avenue and River Street. Just doing the first part will still result in backups, congestion and pollution, and do nothing to improve the lot of pedestrians or cyclists. This plan would improve conditions for all users, and while it would require a major buy-in from Harvard University (which owns the land Soldiers Field Road would be rerouted across), they would be given a major incentive: an Allston campus connected directly to the river (in fact, some of their long-range plans have included decking over part of Soldiers Field Road). Depressing and covering the road would be simple compared to many similar projects (i.e. the Big Dig) as it runs almost entirely through post-industrial brownfields and athletic fields, no major property takings or utility work would be necessary, and much of the route would be closed to trucks, meaning the road clearance would only have to be big enough for emergency vehicles (and, perhaps, transit buses).

I've annotated the map, each letter corresponds to a comment below:

Click to make big!
A: The eastbound Turnpike main trunk would be depressed below the westbound trunk, allowing ramps to overlay.
B: A single westbound ramp would allow access to Soldiers Field Road in both directions, as well as River Street in Cambridge. Western Avenue would be accessed via Soldiers Field Road. Note that if Soldiers Field eastbound were merged with the Turnpike (see below), these ramps would be mostly below-grade; it could be built to allow that sort of conversion at a later time.
C: Soldiers Field east mainline. These roadways, and the ramps on and off of them, would not require truck clearances (but would require clear "no trucks" signage).
D: Cambridge Street could be narrowed to 4 lanes, and narrower yet between ramps. Sidewalks and cycletracks could be elevated to avoid ramp entrances and exits. Traffic from Western Avenue to Cambridge Street via Memorial Drive.
E: Offramp to Cambridge Street would end at a traffic signal.
F: Elevated cycletrack / sidewalk allows cyclists to avoid traffic signal and on/off ramps.
G: River bike path built 12+ feet wide, utilizes one of the disused Soldiers Field underpasses to avoid grade crossings. This would allow a 8-mile traffic-free trip from the Charles River dam west to the Western Avenue Bridge in Brighton by foot or bicycle. The other side of these underpasses would be filled.
H: Separated cycletrack facilites on the Western and River/Cambridge bridges would connected with the grade-separated riverside bike path. The riverside path could be set back from the riverbank, which would be maintained for active and passive recreation.
I: Rebuild the Weeks Bridge with ADA accessibility, and connect to bike paths for a river crossing.
J: The connection between Soldiers Field Road and the Eliot Bridge would be grade-separated; the current connection has a three-phase light in the center. Another option would be a single-point light between the Soldiers Field East-Eliot Bridge and Eliot Bridge-to Soldiers Field East which would reduce grade separation.
K: The current underpasses under the Eliot Bridge for bicyclists and pedestrians would be retained. Sidewalks / paths on the bridge would be used for grade-separated access to south-side pathways.
L: Most of the intersection east of the Eliot Bridge would be rebuilt as a wide swath of parkland.
M: A bicycle bridge would be built across the Eliot Bridge connection, cutting some distance off this route. Grade-separation would be integrated with the Eliot Bridge, and the current Eliot Bridge underpass would be retained (K).
N: Ramps to the current elevated structure would be built not to preclude future grade separation eastbound.
O: Mixing zones on Soldiers Field Road would be three lanes wide, and long enough to allow traffic to merge across two lanes to access various routes (although engineering would be required to determine the optimal length here so as not to bottleneck).
P: Ramps to Western Avenue would be built to specifications for truck traffic; north of this it would be cars-only. Traffic destined to Harvard Square would be routed west on Western and then east on Harvard, or via Memorial Drive.
Q: Ramps at North Harvard Street would be offset to keep construction away from Harvard Stadium. The track would be reoriented after construction.

While adding Soldiers Field Road reconfigurations to the rebuilding of the Turnpike interchange, the project should still not be viewed in isolation but rather as part of the larger transportation network. A few things to consider:
  1. Allowances should be made for future fixed-guideway transit between BU and Harvard.
  2. The entirety of the Turnpike, the railroad tracks and as many ramps as possible could be buried to allow the street grid to be connected across the rail yard from the BU area towards the river.
  3. Instead continuing east along the river, Soldiers Field Road could merge in to the Turnpike. This would require a wider highway (perhaps five lanes in each direction) and require the highway to be rebuilt below-grade to allow for room for the rail line. It would probably also necessitate some sort of exit in the Charlesgate area. This would be moving towards Big Dig territory as far as complexity, although by moving all rail service to North Station via Cambridge on the Grand Junction, enough space could be freed up to phase construction along the Turnpike. It would, however, create a three-mile-long section of riverfront with no roadway between the city and the river. (Paul Levy made this point years ago.)
  4. The Grand Junction, if (3) were built, would have to be fully rebuilt, below grade and with a transfer station at Kendall Square, although this would be a dramatic transit enhancement for the region and worth the investment.
  5. If Soldiers Field Road and Storrow Drive beyond it were replaced, it would recreate the parkland which James and Helen Storrow originally intended along the river. A two-lane parkway-type road could be retained from Charlesgate (which would have the Bowker Overpass flyovers removed) eastward (although this, too, could be in a tunnel) with a wider roadway resuming only past the current tunnel near the Hatch Shell towards Leverett Circle.
In other words, a project as large as proposed for the Allston Tolls should not be viewed in isolation, as its effects—good or bad—will cascade in several directions along the transportation network. With this kind of brownfield, simply rejiggering some onramps—and ignoring nearby bottlenecks and queues—is not enough.

Saturday, November 16, 2013

The ignominious D Street light

Much has been written about Boston's Silver Line (including on this page). It's certainly not rapid, but it is rather convenient: I made it from Kendall Square to Terminal A in 25 minutes. The problem? It should have been 23.

I've noticed in the past that the Silver Line experiences long waits at the D Street grade crossing after it exits the tunnel. On my ride yesterday, I decided to find out just how long, by means of Youtube:

The bus gets to D Street, and proceeds to sit there for not 30 seconds, not a minute, but just shy of a minute and a half! This is a major service failure. The scheduled time from South Station to Logan airport and back is 45 minutes, meaning that if the bus loses 1:30 each time it crosses D Street, 7% of the route time is spent waiting for a traffic light. For the SL2 line, which is a 25 minute round trip, 3 minutes is 12% of the total operating time!

There's this thing called "transit signal priority" which could be employed to eliminate these wait times. A sensor could be placed just outside the WTC station (and a similar one on the inbound run) which would be tripped when the bus passed by (there are already sensors which detect the bus and raise gates when the pass, and which close barriers should someone attempt to drive in to the tunnel). This would give 15 seconds to flash the don't walk sign and change the light, allowing the bus to proceed through the intersection at full speed. Traffic would not be dramatically impacted since there light would only be red for a few seconds when the bus passes, and an algorithm could be put in to place to assure the green cycle for traffic was long enough to avoid backups (but not, you know, not 90 seconds when very few cars pass through; see above).

Transit signal priority (TSP) is not very expensive; even at the high bound it costs $35,000 per intersection. Ridership on the SL1 is, give or take, 8,000 per day. This means that in a year, for one penny per passenger, trip lengths could be reduced by more than a minute. This should be implemented immediately.

What's more, this would result in reduced operation costs for the MBTA. Buses cost somewhere on the order of $100 per hour to operate. Even if the average time savings per bus was only 30 seconds, this would equate to 4.5 hours of operating time per day, or a $450 savings. Assuming a $35k cost for TSP implementation, it would pay for itself in 78 days—two and a half months.

The argument could be made that these times would just be built in to schedule padding at the end of the route and savings would only be from the reduced power use related to not stopping and starting. But, especially on the SL2, saving a couple of minutes could be used to decrease the overall route time and increase service, something the Seaport District desperately needs. At rush hour, decreasing the trip time from 25 to 23 minutes would allow headways to drop from 5:00 to 4:36—a capacity increase of 8%—without any additional cost. This would allow for 3 additional round trips at rush hour, or 75 additional minutes of service, which would save the T $125. By this metric, the payback would be $250 per weekday, and take 140 weekdays to pull in to the black. That's 7 months. After that, it's gravy.

(Another improvement: extending overhead wires along the whole of the SL2 route would allow the buses to operate without a change of power twice per trip; combined with the savings at Silver Line Way this might allow service to operate at 5 minute headways with 4 buses—a dramatic savings, albeit one with a higher initial capital cost.)

There is no logical reason that transit signal priority should not be immediately procured and installed at D Street. There is no need for a time-consuming review process; the benefits are clear and any disruption to traffic will be far less than the current disruption to the traveling public. While the Silver Line is still hobbled by a convoluted route system, low capacity, slow tunnel speeds, traffic and a poorly-designed power switch (often requiring the operator to exit the bus and manually raise the trolley poles), this inexpensive change would be a good start to dramatically improve service.

Wednesday, November 13, 2013

Hyperloop as the Concorde

An article about the Hyperloop recently crossed my Twitter feed. Now, normally I wouldn't really spend much time on this topic, but this article is particularly risible. Why? Because the backers of the project are now favorably comparing it to the Concorde.

No. Seriously:
“It’s similar to what the Concorde did for air transport … This will revolutionize how we transport people from city to city.”
Oh, lordy. Here's what the Concorde did for air transport. It created a very small, niche industry which offered a somewhat faster product than what existed. This product was available only at a huge markup to the main market. It had severely constricted capacity. Development cost 12 times (*) initial estimates (so much so that it is an above-the-fold example in the "cost overrun" Wikipedia article). It received massive government subsidies. And after 30 years of serving a very small market, it was retired from service.

Let me repeat that: the Concorde is no longer in service. It didn't revolutionize how we transport people by air. It first flew in 1976, and last flew in 2003. The 747 first flew in 1969, and continues to transport people by air today. If the Concorde had revolutionized how we transport people from city to city, we'd probably still be using it today. We're not. The jet? It revolutionized travel—before that most everyone crossed long distances of water by boat, and on land by train. The Concorde? We're still flying conventional jets.

And they're crowdsourcing this? Let me just take a flyer here. Elon Musk scribbled some ideas on a napkin (and the Tesla is doing great, at least when it's not catching fire) and now a couple people are crowdsourcing the project, and comparing it to something that, while a technological marvel, was for all intents and purposes, a financial disappointment.

However, unlike the Concorde, I doubt the Hyperloop will ever get off the ground.

(* Note that with the same level of overrun, the Hyperloop would cost $72 billion to construct, which is as much as the High Speed Rail proposal. Except the High Speed Rail system can carry 10 times the passenger load (or more). Remember, the Concorde only had 100 seats. Most everyone else flew—and still flies—on conventional jets.)

Friday, October 25, 2013

How schedule adherence affects headways

There's an article on TheAtlanticCities which is bouncing around the office about how painful it is to wait for a train (I'd add: especially if you don't know when it might come). But even with the proliferation of countdown timers (except, uh, on the Green Line), any disruption to the published (or, at least, idealized) headways can cause headaches. And when headways get at all discombobulated, passenger loading becomes very uneven, resulting in a few very crowded trains that you, the passenger, are more likely to wind up waiting for and squeezing aboard.

For instance, let's say that you ride the Red Line in Boston. The published headway is 4.5 minutes (two lines, 9 minute headways for each line). Assuming you're going south through Cambridge, the agency should be able to send out trains at the exact headways from the two-track terminus, barring any issues on the outbound run. You'd expect that, upon entering the station, you'd have an average wait of 2:15, and the longest you'd ever wait for a train would be 4:30 (if you walked in just as the doors were closing and the train was pulling out of the station).

In a perfect world, this would be the case. In the real world, it's not. In fact, it probably seems to many commuters that their average wait for the train is more in the four-minute range, and sometimes as long as seven or eight minutes. And when a train takes eight minutes to come, the problem compounds as service bunches: the cars get too full, and dwell times increase as passengers attempt to board a sardine-can train and the operator tries to shut the doors.

Here's the rub: even if most services run on a better-than-average headway, passengers are more likely to experience a longer wait. Here's an extreme example. Imagine a half hour of service with five trips. With equal headways, one would arrive every six minutes, and the average wait time would be three minutes. Now, imagine that the first four services arrived every 2.5 minutes, and the final one arrived after 20 minutes. The average headway is still six minutes. However, the experienced average is far worse. Unless the services operate at that frequency due to load factors, passengers likely require the service at a constant (or near-constant rate). Imagine that one passenger shows up each minute. The first ten are whisked away quickly, waiting no longer than three minutes. The next 20 wait an average of 10 minutes, with some waiting as long as 20. In this case, even with the same average headway, 14 passengers—nearly half—wait longer than the longest headway if the service was evenly-spaced.

I used the Red Line as an example because I have experience with this phenomenon, and also data. Back when I first collected Longfellow Bridge data, I tracked, for two hours, how often the trains came. It turns out that the headway is actually 4:10 between 7:20 and 9:20, more frequent than advertised. However, nearly half of the trains come within three minutes, which means that there is a long tail of longer headways which pulls the average down. So instead of an average wait time of 2:05, the average user waits quite a bit longer.

Assuming that each train carries all passengers from each station (not necessarily a valid assumption), the average customer waits 2:32. This doesn't seem like a long time, but it means that while the trains are run on approximate four minute headways, the actual experience is that of five minutes, a loss of 20% of the quality of service. Five minute headways aren't bad. The issue is that there are several periods where customers wait far longer than five minutes, resulting in overcrowding on certain trains, and longer waits for the same ones. The chart below shows wait times for each minute between 7:23 and 9:23. Green is a wait of 2:15 or less, yellow 4:30 or less (the advertised headway). Orange is up to 6:45, and red is longer. About one sixth of the time a train is running outside of the given headways. And three times, it is longer than 150% of the advertised headway.

Another personal observation is that, try as I might, I seem to always get caught on a packed-full train. This is due to the same phenomenon. Of the 30 trains noted, only eight of them had headways of more than 4:30. Those 8 trains—which, assuming a constant flow of riders, accounted for 27% of the passengers—served 56 of the 120 observed minutes, carrying 47% of the ridership! Ten trains came within 2:30 of the previous trains. These trains accounted for 33% of the service, but only served 19% of the ridership. So while one-in-three trains is underloaded, you only have a one-in-five chance of getting on one of those trains. And while only about a quarter of services are packed full, you have a nearly 50% chance of riding one of those trains. So if you wonder why it always seems like your train is packed full, it's because it is. But there are just enough empty services that once a week you might find yourself in the bliss of a (relatively) empty train car.

Overall, I mean this as an observation of headways, not as an indictment of the MBTA. Running a railroad with uneven loads (especially at bus- and commuter rail-transfer stations), passengers holding doors and the like can quickly cascade in to a situation where certain trains are overloaded, and others pass by with plenty of room. Still, it's infuriating to wait. But it's interesting to have data, and to visualize what it looks like during the course of what seems to be a normal rush hour.

(On the other hand, there are some services, like the 70 bus, which have scheduled uneven headways and where the actual level of service is significantly impacted, but that's the subject of another post entirely.)

Sunday, October 20, 2013

The weather is cooler. The Longfellow is the same.

Twice this summer, we counted vehicles on the Longfellow. Between June and July, when the lanes of the bridge were shifted and constricted, bicycle traffic was level (well, actually, it rose slightly) while vehicular traffic decreased. I was otherwise occupied this September and didn't get a chance to do a comparable bike count until last week, when I eked out an hour to sit on the bridge.

And the results are so mundane they aren't even worthy of charts and graphics. Basically, the numbers were within a thin margin of error of those from July:

(All values for peak-hour of the count, note that the Longfellow runs east-west; Eastbound towards Boston, Westbound towards Cambridge)

Eastbound Bikes: 308 (July: 298)
Westbound Bikes: 63 (July: 68)
Eastbound Pedestrians: 65 (July: 83)
Westbound Pedestrians: 191 (July: 201)
Inbound Vehicles: 411 (July: 415)

So the bridge, even after two months of people getting used to the traffic patterns, has seen no major changes. Any drop in non-motorized use might be attributable to cooler weather (in the mid 50s rather than the upper 60s) or to random variance. And assuming a normal traffic day, there has been no significant increase in traffic since the bridge has opened.

It's the last piece that I find most interesting. It really speaks to the concept of "induced demand." With the wider Longfellow, we say 800 vehicles per hour traversing the bridge in June. Once the bridge was narrowed, that number fell to 400. There were weeks with dozens police directing traffic, but the number of cars very quickly hit a new equilibrium. People do not seem to need a major education campaign to figure out where to go. If the new roads are gridlocked, they'll find alternate routes. The system has not ground to a halt (although inbound at the evening rush often backs up the length of the bridge). There are too many variables to find out if people have switched to other routes or modes or just not made the trip, but traffic in the morning across the Longfellow has not been the apocalypse.

Thursday, October 10, 2013

Boston's Worst Traffic Day of the Year

It's tomorrow. The Friday before Columbus Day.

I have no actual data to back this up. Only anecdotal and empirical data. (Oh, and data from the Pike, which claims it's second to the Friday before mother's day in May, but I think that might be just for the Pike without the added benefit of every road north and south of the state, too. How prescient that this article comes out right after I post this.) But here's what happens, and here's how to avoid it.

Boston sees a lot of bad traffic. In the winter, when everyone is in town and weather hits, the entire system can grind to a halt. (The worst I know of was in December 2007 when a storm hit Boston around noontime. Snow fell heavily from the onset with temperatures in the mid-20s, so roads iced over. So many people left work early to beat the weather home that the roads filled up completely and plows couldn't keep them clean. So the entire network ground to a halt until snow let up late in the evening.) But you can't really plan for that. In the summer, Boston sees epic traffic jams headed out of the city to and from vacation spots, especially getting on and off of Cape Cod (the eight hour, 25-mile backup this July 4 this year was particularly bad), although other bottlenecks in New Hampshire and Western Mass can be painstakingly slow.

But the Friday before Columbus Day Weekend is the worst. Here's why:

  • It's the Friday before a long weekend. So in addition to Friday traffic, you have the masses headed on vacation, too.
  • But it's a normal Friday. Of all the three-day weekends in the calendar, it's the only one that almost no one extends. So there aren't many people who get away a day early to ease the traffic.
  • It's the last nice weekend of the year, for foliage and, often for weather. It's still a pleasant time to go to Cape Cod, or the Berkshires, or Northern New England before the leaves fall and the temperatures plummet.
  • Not many people stay in town for the weekend. On Patriots Day (Marathon), July 4 (Fireworks), Labor Day, MLK Day and Memorial Day there are parades and ceremonies and the like that people attend locally. No one is celebrating Columbus anymore.
  • Oh, yeah: everyone from New York, Connecticut and Rhode Island wants to get to Vermont, New Hampshire and Maine. So guess where they all go? Massachusetts.
Personally, I've sat for two hours to go 10 miles on 128 on this wonderful day. I've also had a four hour drive from Springfield to Boston on the Turnpike. And my uncle had a three-hour trip from Providence to Boston, which culminated with him blindly following directions off of the Southeast Expressway on to Mass Ave when informed the Expressway wasn't moving.

These weren't due to accidents, but to volume. The system operates at-or-near capacity on a normal day. Add the factors above, and it is pushed way over capacity. Once that happens, everything stops.

But there are some suggestions. First of all, go where you are going later. We have wonderful apps and data and the ability to look at a computer screen and find out how long a trip is going to take. Take a look at Google Maps, or at MassDOT's traffic map or data stream, and wait it out. As long as you plan to wait it out, you can sit by the river or go for a run and wait until the coast is clear (which should happen by 7 or 8 p.m.). Second, consider back roads, especially further from the city. Much of the congestion comes tourist-types descending on to main highways. People who don't normally drive the roads don't know about parallel options, and people who are unprepared for their onslaught get caught up in the hubbub. So if the Pike is a royal mess, try Route 9. If 93 is a parking lot, come through the city. 

The saying goes "if you can't beat 'em, join 'em." But that's stupid. If you can't beat 'em, either wait patiently, or find a route where they aren't. Because if you don't, you too will get to enjoy the Worst Traffic Day of the Year!

Friday, August 16, 2013

Mass State Police need to learn about bicyclists

Dateline: July 30, 2012. Cambridge.

I bicycle across the Harvard (Mass Ave) Bridge towards MIT (westbound). I signal in to the traffic lane to overtake a slower cyclist and to avoid a particularly rough stretch of pavement. Upon stopping for a light at Memorial Drive, the State Trooper tasked with directing traffic walked over.

"You're not supposed to do that," he said.

"Do what?"

"You can't leave the bike lane to pass other vehicles."

"Officer, I am allowed to leave the bike lane if conditions warrant, and this includes when pavement conditions are dangerous, or to overtake another vehicle."

"No, you must stay in the bike lane. You can only leave the bike lane where it is dashed, at intersections like this," he said, pointing to where the bike lane crosses Memorial Drive."

At this point, he asked me if I would like to discuss this further. I was glad to. So he proceeded to write me a citation.

Here is what I was cited for:
85.11B: Pass No Pass Zone
85.11B: Fail to Stay Within Marked Lanes
I asked the officer to explain the citations. He refused. (This may be a violation of MGL 90C.2 which states that "[a] Said police officer shall inform the violator of the violation and shall give a copy of the citation to the violator.") I asked him to please give me his name. He refused, and pulled his reflective vest over his name badge. He then took out his handcuffs and called for backup, asking me if I was being disorderly. Not wanting to further escalate the situation (and, sadly, not having a witness there to video the situation) I asked if I was under arrest and, upon being told that I was not, left.

And filed a complaint with the State Police.

I don't want to dwell on the intimidation by the State Police; that will be dealt with internally. However, I would like to deal with the fact that the Mass State Police apparently do not understand bicycle law. (According to the ticket code and internet, the officer works at SC5, which is the Sturbridge Barracks. So, a) he's probably not going to show up in court in Middlesex and b) he probably doesn't cite a lot of cyclists.) First of all, bicyclists do not have to stay within bike lanes.

First, passing in a no passing zone. This would appear to fall under MGL 89.2. Here is the pertinent text from the law:
If it is not possible to overtake a bicycle or other vehicle at a safe distance in the same lane, the overtaking vehicle shall use all or part of an adjacent lane if it is safe to do so or wait for a safe opportunity to overtake.
It is, therefore, legal to change lanes to pass in the same direction. Additionally, the Massachusetts driver manual states that it is legal to cross solid white lines in a vehicle (see this PDF, page 10). In other words, a white line does not constitute a no passing zone. And none of this is mentioned in the cited section, 85.11B

Second, failure to stay within marked lanes. This falls under MGL 89.4A and 89.4B. It states, amongst other things, that:
Upon all ways the driver of a vehicle shall drive in the lane nearest the right side of the way when such lane is available for travel, except when overtaking another vehicle or when preparing for a left turn.
Since I was overtaking another vehicle, I was subject to this exception (there is a separate exception in 85.11B for dangerous situations, and the poor pavement in the bike lane on the Harvard Bridge would obviously fit within this exception). Additionally, while I did signal my turn, I am not required to do so if I need to keep both hands on the handlebars. The officer said that my left hand was extended to "wave off traffic" which is an interesting interpretation of the law from someone whose job is to enforce it.

Had the officer wanted to charge me with these offenses, he probably should have referenced them based on the actual statute. 85.11B simply refers to these statutes.

But, of course, I wasn't in violation of either.

I expect this case to be dismissed without a hearing; it is likely that whatever magistrate vets the citation will not deem it worth the court's time. If, however, a hearing date is set, I will make sure that it is well publicized. You're all invited.

Update 10/21: I asked a State Trooper today on detail at the Head of the Charles if it was legal to leave a bike lane to pass another cyclist. He said it was perfectly legal.

Update 11/19: A court date has yet to be filed. Apparently it should be within 30 days. If it's much longer, I could probably move to dismiss based on the delay.

Update 2017: I received a court date and asked for the charges to be dismissed. The officer had written that "I had created a situation where there were many cars honking at me." I asked the Trooper there (not the same one) to look at the pictures and I showed where he was standing and where I was cycling and asked "do you think it is reasonable to assume that, in a busy intersection in Boston, it would be possible to ascertain which of several dozen vehicles was honking?" The case was decided in my favor.

I never did hear from the State Police regarding my complaint.

Wednesday, August 14, 2013

Monorail vs Hyperloop

There's a lot of hubbub going on about Elon Musk's, uh, fanciful "hyperloop" idea coming out of California. There's a lot of fawning in the press. There are people who know things writing long missives taking down most every bit of the lack of details in the report.

In any case, I think there's another angle here. Basically, the fact that the Simpsons predicted this 20 years ago. And not only did they predict it, but there are some uncanny parallels. Of course, I refer to the Marge vs. the Monorail which first aired in 1993. Not only is it surprisingly prescient, but hilarious, too, making several best-of lists of Simpsons episodes, and being called "the best sitcom episode ever." (And it was written by the inimitable Conan O'Brien, who would go on to some other fame. You can watch via a sketchy link here.)

Basically, the premise is that serial villain and nuclear power plant owner C. Montgomery Burns is caught illegally disposing of nuclear waste, and pays the town $3 million in fines. The town then has a meeting to decide what to do with it. From here on in, I'll parallel it with the LA-San Francisco transportation corridor:

Simpsons: after several proposals and ideas, Marge leads the outcry to repair the town's main street.
California: after several fits and starts, the state passes bonding for high speed rail.

Simpsons: Huckster Lyle Lanley, after the town has approved the street idea, shows up with a plan for a monorail, leads the town in song, and the Main Street (proven transportation improvements) is replaced with a mock-up model of the monorail.
California: After the state has all but started construction on high speed rail, Elon Musk shows up with a sketch of an idea for a hyperloop, which will be faster, cheaper and better than the high speed rail.

Simpsons: The townsfolk ask Lanley questions with the following exchanges:

I hear those things are awfully loud—It glides as softly as a cloud.
Is there a chance the track could bend?—Not on your life, my Hindu friend.
What about us braindead slobs?—You'll be given cushy jobs!

California: Questions about where the system runs, its technical merits and such are not addressed.

Simpsons: Monorail runs on solar power.
California: Hyperloop runs on … solar power.

Simpsons: Lanley has sold monorails to Brockway, Ogdenville and North Haverbrook
California: Musk hasn't sold a hyperloop to … anyone.

It turns out that Lanley builds shoddy products, and that in the end the monorail winds up running at warp speed (slowing temporarily during a solar eclipse) before again running out of control, only stopping when Homer uses an M attached to a lasso to hook a giant doughnut (eliciting the line "Doughnuts, is there anything they can't do?").

So basically, in both cases, the citizens have a pressing transportation issue and appropriate money to fix it. In both cases, they make a choice based on proven technology only to have it upended by an unproven idea (perhaps more nefarious in the case of the Simpsons). Both systems run on solar power, but at least with the monorail there were proven (and proven bad) systems Marge could visit to disprove its worth. If the case of the hyperloop, if it somehow upends the high speed rail project and succeeds, I'll be glad, if surprised. But I'd more likely expect a monorail.

Friday, August 9, 2013

The next step on the BU Bridge area for bikes

The City of Boston recently made somewhat dramatic improvements to the bicycle facilities along Commonwealth Avenue. The formerly orphaned bike lane has been restriped through the intersection, and the new paint is all bright green. In addition, there are reflectors in the road to the right of the lane which I can attest are very visible from a vehicle at night. It's a good start.

Meanwhile, Brookline has installed contraflow bike lanes on Essex Street to allow cyclists to go from Essex to Ivy to Carlton and allow a low-traffic alternative to get from the BU Bridge to the Longwood area. (And for those of us headed to Coolidge Corner, another block before we take a right.) Going towards the bridge, the town has striped in a bike lane. And, more importantly, they've cut a "bicycle crosswalk" across the BU Bridge loop (Mountfort Street) to allow cyclists to get from the Brookline streets to the BU Bridge without having to cross medians, loop around through the intersection of death, or ride the sidewalk to the light. It also allows cyclists coming from Brookline to skip Commonwealth altogether, a great boon to cyclists who don't want to ride one of Boston's widest and busiest streets. So, what was once a death trap for cyclists—and is still rather cumbersome—is getting better. (The picture at right shows the bike lane in the foreground and the crossover in the background.) There is some background information in this document.

The next step, I think, is to better allow cyclists coming from the west on Commonwealth and headed towards Cambridge, would be a two-stage bike turn box. This is not a new concept—it even exists in Boston—and goes as follows:

  1. An eastbound cyclist on Commonwealth approaches the BU Bridge.
  2. The cyclists, upon a green light, goes through the light, then pulls in to a separate line to the right of the bike lane and turns their bike towards the bridge.
  3. Once the light changes, the cyclist pedals straight across and in to the bike lane on the bridge.
Here's a picture of the current facility, with an idea of a two-stage bike box sketched in, as well as a bike box for cyclists coming from Mountfort:

I would hope this is on Boston Bikes's radar screen (if it's under their jurisdiction and not the state). It would be a great help to more novice cyclists who may not know it's an option. The rest of us already do it.

Thursday, August 1, 2013

One chart shows the change in Longfellow traffic

Boston’s massive reconstruction of the Longfellow Bridge began this month. Over the next three years, traffic will be severely restricted, bicyclists mostly accommodated, and rail traffic mostly maintained across a major link in the transportation system which carries 100,000 transit riders as well as several thousand bicyclists and pedestrians across the Charles River (and some vehicular traffic, too).

In late June, I took a baseline, pre-construction count of morning, inbound traffic across the bridge. With the new traffic configuration in place (an inbound bike lane, a travel lane, a pylon-lined buffer and an outbound bike lane, plus the sidewalk) I decided to take a new snapshot of the bridge traffic. Had traffic declined with fewer lanes available? Are cyclists shying away from the new configuration?

Here’s what I found, summed up in one chart:

Bicycle counts stayed about the same (they actually rose, overall, and the peak hour saw 308 cyclists, an increase 14%). Vehicle counts, however, showed a dramatic drop, declining by 50% from 840 to 400 during the peak hour of use! It’s interesting that this is not due, necessarily, to restricted capacity (the one lane of traffic didn’t back up beyond the midpoint of the bridge at any time when I was counting, although the afternoon is a different story) but perhaps the perception of traffic, and the fact that the single lane reduces traffic speed quite a bit.

No lack of praise should be given to MassDOT for this iteration of the Longfellow traffic pattern. The bicycle facilities are, if anything, improved over the bridge before, especially considering the much lower vehicular traffic speeds and volume. And there is no lack of cyclists—even on one of the quietest weeks for traffic midsummer, there were more bikes than a day with similar weather in June.

A few other tidbits:
  • Bicyclists and Pedestrians accounted for 60% of the traffic on the bridge. Cars transported fewer people than human power. (See diagram below.)
  • Between 8:30 and 8:45, there were actually more bicyclists crossing the bridge than vehicles.
  • Pedestrians of all types outnumber cyclists (although this includes both joggers and “commuters”—as defined by me—in both directions).
  • The flow of “commuting” pedestrians is a mirror image of bicyclists. There are four times as many Boston-bound cyclists as Cambridge-bound, but more than twice as many Cambridge-bound Pedestrians as Boston-bound. (There are fewer joggers, but they exhibit a preference towards running eastbound across the bridge, differing from the other foot traffic.) Overall there are more bicyclists going towards Boston and more pedestrians towards Cambridge.
  • While 24 Hubway shared bikes accounted for only 5% of inbound bicycle trips, the 20 outbound Hubways made up 18% of the Cambridge-bound bicyclists.
  • Only four cyclists used the sidewalk, and only one rode the wrong way in the contraflow lane. (I yelled at him.)
And one more diagram showing bridge use (for the record, one chart, one diagram and one infographic, and one annoying and slightly misleading title):

Thursday, July 25, 2013

Personal data collection: Hubway

Back in 2011, as part of a convoluted New Year's resolution, I started tracking my personal travel daily. Each day, I record how many miles I travel, by what mode, and whether I am traveling for transportation or exercise/pleasure. Why did I start collecting these data? Because I figured that there was the chance that some day it would be useful.

And that day is … today!

I realized recently that I had a pretty good comparative data set between the April to July portion of 2012 and 2013. Not too much in my life changed in that time frame. Most days I woke up, went to work, came home and went for a run. Probably the biggest difference, transportation-wise, was that in 2012 there were no Hubway stations in Cambridge, and in 2013 there were. In addition, since Hubway keeps track of every trip, I can pretty easily see how many trips I take, and how many days I use each mode.

To the spreadsheets!

The question I want to test is, essentially, does the presence of bike sharing cause me to walk and bike more frequently, less frequently or about the same? Also, do I travel more miles, fewer or about the same? A few notes on the data. First, I am using April 6 (my first Hubway ride in 2012) to July 9 (in 2012 I had a bike accident on the 10th and my travel habits changed; Hubway launched in Cambridge at the end of the month, anyway). Second, I collect these data in 0.5 mile increments, and I don't log each and every trip (maybe next year) but it's a pretty good snapshot.

The results? With Hubway available, I ride somewhat more mileage, but bicycle significantly more often. In addition, my transit use has declined (but I generally use transit at peak times, so it takes strain off the system) and I walk about the same amount.

Here are the data in a bit more detail for the 95 days between April 6 and July 9, inclusive:

Foot travel. In 2012 I walked 84 days in the period a total of 190.5 miles. In 2013, the numbers 83/180. (Note that I do not tally very short distances in these data.)

Bicycle travel. In 2012, I biked 66 and, believe it or not, in 2013 I actually biked fewer days, only 64. As for the distance traveled, I biked 466.5 miles in 2012, and 544.5 miles in 2013. So despite riding slightly fewer, I biked nearly 20% more distance. This can be partially explained by my participation in 30 Days of Biking in 2012, when I took many short trips in April.

In addition, in 2013 I began keeping track of my non bike-share cycling trips. I only rode my own bike 14 days during the period, tallying 44 trips on those days. But there were many days where I rode my own bike and a Hubway; I took 29 Hubway trips on days I rode my own bike; on 8 of the days I rode my own bike, I rode a Hubway as well.

Bike share trips. In 2012 I rode Hubway on 39 days, totaling 71 rides, an average of 1.8 Hubway rides per day riding Hubway. In 2013, I rode Hubway on 58 days, but tallied 185 rides, an average of 3.2! So having Hubway nearby means that I ride it more days, and more often on the days I ride.

Transit. In 2012, I took transit almost as frequently as bicycling, 61 days. I frequently rode the Red Line to Charles Circle and rode Hubway from there to my office. In 2013, my transit use dropped by nearly half, to just 31 days, as I could make the commute by Hubway the whole way without having to worry about evening showers or carrying a lock.

We might look for the mode shift here. My walking mode shift has not changed dramatically. My bicycling mode shift hasn't appreciably increased, although the number of total rides likely has. My transit mode shift has decreased, as I shift shorter transit rides to Hubway.

Now, if they ever put a station near my house, I'll get to see how those data would stack up. My hypothesis: I'd never walk anywhere, ever.

Tuesday, July 16, 2013

Longfellow bus-bike illogic

The Longfellow project is set to begin next week—signs have been flashing across the city advertising the multi-year lane closure—and at a meeting last week (documentation here), concerns were aired about traffic, gridlock, and banning bicycles from the roadway when the T is closed and buses traverse the bridge.

Wait, when the T is closed and transit riders are shunted on to a bus shuttle, were going to prohibit cyclists from crossing the bridge? When there are Hubway stations on either end? When buses will be packed with weekend travelers and trip lengths will be 10 or 20 minutes longer than usual? When taking a few people out of the system would reduce crowding and speed up trips for everyone else?


MassDOT and the MBTA had been cagey about this, never outright saying that bikes were verboten until very recently, when their language was challenged (what does "emergency bike/bus lane" mean, anyway?) by cycling advocates.

In a recent email to stakeholders, MassHighway administrator Frank DePaola wrote:
There have been recently a few tragic incidents between Busses [sic] and bicyclists one common factor has been tight clearances and the bicyclist on the right hand side of the bus. During a red line bus diversion the frequency of busses [sic] between Kendall and Park Street will be quite high the probability of an incident on the tight quarters of the bridge, especially at the approaches is too high and safety is a big concern.
Let me attempt to rephrase:
There have been multiple crashes where buses have hit cyclists when passing them. If we get rid of the bikes, we won't have to worry about these any more.
Never mind the fact that these bicycle-bus incidents have occurred with buses in normal operation, on roads with other vehicles, many distractions, and with buses pulling in and out of bus stops. The Longfellow, while narrow, won't have any of this. There are no bus stops on the Longfellow. There will be no other cars on the Longfellow at this time. When a bus pulls out of a stop, the driver has to worry about cyclists passing on the right and cars going around on the left, while at the same time worrying about the rider running up and tapping on the door to try to get on the bus. None of this will take place on the Longfellow. Yet the default policy is to ban bikes.

While this is dismaying to the cycling community, it seems to be almost insulting to MBTA drivers. It almost says to them that the T and MassDOT don't have faith in them to successfully pass cyclists—something they do thousands of times per day in heavy traffic—on an otherwise closed roadway. I'm sure that experienced MBTA bus drivers can drive across the Longfellow and pass cyclists at the same time.

A salient issue is the pinch point at the Boston end of the bridge, where the width reduces from 29 feet to 22 feet for a 300 foot stretch. This is of concern, but could be remedied with a simple instruction to bus drivers: do not pass cyclists on this section of bridge. There is no need to erect signage to get this point across; MBTA supervisors could remind drivers of the policy before each shift crossing the bridge. (The narrowness of this portion of the bridge is another reminder that two-way vehicle traffic at any other time should be a total non-starter, especially since bicycle counts have actually increased since the new bridge configuration.)

Yes, this will result in some measurable delay for bus passengers. But these delays, I think, would be minimal. Let's run some (estimated) numbers:
  • The MBTA will have up to 15 buses on the Red Line loop to serve passengers. Assuming the route takes 15 minutes (it will likely take slightly longer) this is an average of 1 bus per minute.
  • Each bus will carry 50 passengers (35-40 passengers plus standees).
  • The 2011 bicycle/pedestrian counts found an average of 30 bikes per hour in each direction crossing the Longfellow midday on weekends. While numbers may have climbed since, some cyclists will choose other routes due to the construction, so this is a fine estimate.
  • Cyclists on this section will average 8 mph going towards Cambridge (uphill) and 16 mph towards Boston (downhill).
So let's run some scenarios. A bus traveling at 20 mph will traverse the 300 foot narrow section in approximately 10 seconds. Thus, an inbound bus which would have to slow behind a cyclist going 16 mph would lose 3 seconds. An outbound bus would have more of a time penalty; following a cyclist for 300 feet through this pinch would take 25 seconds to cover 300 feet, a delay of 15 seconds. 

But how often would there be any conflict between a bus and a cyclists in this section of roadway anyway? It is not like there will be a constant line of buses or a constant stream of cyclists. Let's assume a buffer for both buses and cyclists regarding any bus/bike road conflict of double the actual time needed to traverse the segment. For buses, it would mean that the would occupy these 300 feet of roadway 33% of the time (20 seconds every minute). For inbound cyclists, they would occupy the roadway 22% of the time (26 seconds every two minutes). Outbound cyclists would occupy the roadway 42% of the time (50 seconds every two minutes).

Let's do some math. For inbound traffic, there would be a potential conflict 7.5% of the time. This would delay 4.5 buses per hour an average of 3 seconds each, for a total of 13.5 seconds per hour. Assuming 50 passengers per bus, this would be a total of 675 seconds of delay per hour. (Although this might be even less as buses would slow to cycling speed or lower to navigate the turns at Charles Circle.)

For outbound traffic, there would be a potential conflict 14% of the time. This would delay 8.4 buses per hour for an average of 15 seconds each, for a total delay of 118 seconds per hour. Again, if we assume 50 passengers per bus, this is a total of 5880 seconds of delay per hour. (This too might be less as buses accelerate up the bridge approach at a slower average speed.)

This is a total of 6555 seconds of delay for bus passengers per hour. However, this is actually a pretty small number. If there are 50 passengers per bus in each direction, and one bus crossing the bridge every minute, there will be 6000 passengers per hour. Thus, the total delay per bus passenger by allowing cyclists on the bridge (and having buses not pass them in the narrow section) will be just 1.1 seconds per passenger. Considering that the total delay due to Red Line closures will amount to 10 to 20 minutes, this will just 1/500th to 1/1000th of the total detour. In other words, any delay caused will be negligible.

We can also attempt to quantify the delays for cyclists who would be rerouted around the bridge. There are many fewer cyclists, but the potential detours result in a much longer delay. Requiring cyclists to use the Harvard or Craigie Bridge will add 2 to 4 minutes to a trip from Park Street to Kendall. With 60 cyclists per hour, this would equate to 180 minutes—or 10,800 seconds—per hour, far higher than the total delay for bus passengers.

In addition, there are two temporary signs which, I think, would be perfectly acceptable to the bicycling community and which will help mitigate potential conflicts further: First, on each side of the bridge, there should be a sign reading
This will remind cyclists that there are buses passing on the bridge. The second sign, approaching the outbound side in Boston, would read:
This would mean that if a bicyclist and a bus approached the choke point at the same time, the bus would go ahead, and the bicyclist would then be able to navigate the narrow section before the next bus enters the bridge. This would reduce potential conflicts, as well as reducing the need for buses to pass cyclists in this narrow section.

A better policy than hoisting "no bikes" signs would be to allow bikes, and evaluate any issues which arise. This is the policy they are taking towards Mass General, TD Bank and other institutions which are insisting than closing the road to traffic will result in so much gridlock the people won't be able to get home from sporting events or concerts (seriously) or home from the hospital (a major reason the inbound direction was selected to be kept open was to allow emergency access to MGH). If we are going to make concessions to these groups, we should do the same for cyclists who will actually help to alleviate congestion during the closure times.