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.)