MBTA Silver Line
Examination of the comparative cost, cost effectiveness and
functionality of a Mid-Block Station
At the stakeholders' meeting convened by Congressman Capuano, some concerned abutters
suggested further exploration of the so-called "mid-block station." This had been considered
previously and rejected by MBTA in the consideration of how best to extend the Silver Line,
because of concern with the grade problems of reaching the TNEMC portal at Washington Street,
and quality of transfers from the Green and Orange Lines, but MBTA agreed to do further
analysis of these issues and report back. The intended benefit of this "mid-block" approach
seems to have been to avoid disruption to Eliot Norton Park, and a belief that a single mid-block
station might be less expensive than a two-station solution. Further analysis of options has
developed two other ways to avoid Eliot Norton Part: the Tremont Alternative and the Columbus
Ave alternative. Moreover, when it is recognized that a turn back is required to accommodate 2/3
of the service to achieve an efficient service plan, the single station does not cost less than the
two-station plan, so there is no point in violating the standards for steep grades, or considering
the inferior transfer experience the single station would impose on the MBTA’s riders. For all of
these reasons, the MBA continues to consider the "Boylston/Essex Core Alignment" the
appropriate refinement of the 1993 Approved Record of Decision. It straightens the previous
approved alignment, avoids disrupting Avery Street by the new Ritz Carlton Hotel complex. This
refined alignment reduces impact on the Boston Common by relocating the turn back loop to
under the Boylston/Charles intersection, while achieving equivalent quality Green-to-Silver and
Orange-to-Silver transfer opportunities provided in the 1993 Approved Record of Decision, and is
compatible with three extensions to connect Washington Street and Back Bay, one via Tremont
to a TNEMC portal, one via Charles to a TNEMC portal, and one via Columbus. Two of these
avoid Eliot Norton Park, cost no more than the single combined station/Tremont Park, and
provide better service. This paper attempts to explain and summarize these issues and to
present the MBTA’s reason for not continuing to examine this alternative.
In determining the benefits and liabilities of this proposal, the MBTA examined the project in light
of three basic yet critical review standards. These standards include:
1. Conformance to MBTA Design Engineering and Construction Standards
2. Station Functionality and Transit Operations
3. Cost (both capital and operating costs) as well as Cost Effectiveness as measured by the
Federal Transit Administration (FTA).
This paper summarizes the “Mid-Block Alternative” when screened against these criteria and
compared to the two-station Alternatives. A graphic of each alternative is attached.
1. Conformance to MBTA Design Engineering and Construction Standards
The MBTA has established design and engineering criteria that act as the basic rules by which a
project such as the Silver Line is designed. These criteria come from a variety of sources
including recent studies and recommendations and are the result of experience learned by the
MBTA in its operation of the transit system over the past 100 years. Additionally, the MBTA
monitors the engineering and transit industries to determine the success and results as realized
by other transit systems around the world.
In the design of the Silver Line, there are many engineering standards that must be addressed.
Most importantly to the Mid-Block Alternative is the issue of maximum grade of the travel way.
Grade is simply the slope or the ratio of the amount of increase or decrease in the elevation of the
travel way across a certain horizontal distance expressed as a percentage. For example, a
1
tunnel that rises four feet over a 100 foot run is said to have a grade of 4%.
that does not rise or lower over the distance is said to have a grade of zero.
A level travel way
Grade and dwell time plays an important role when operating the system. The steeper the grade,
the more power required to move the vehicle up and down the incline (propulsion ascending,
braking descending). Because more power is required to move the vehicle on a steeper grade
the wear and tear on the vehicle is greater, reducing the useful life of the vehicle. Lastly, and
perhaps more importantly, it is at steeper grades that the vehicle is likely to fail and cause delays
to the system. Break/mechanical failure and wheel to rail slippage at steeper grade might cause
and accident and even derailment. Also, it will be difficult to climb up at slower speed or starting
form zero speed at incline.
During the initial planning for the Silver Line, the MBTA established maximum grades for the
system considering recent study reports znd their recommendations on grade for the new transit
design. A committee of MBTA staff from Design and Construction, Safety, Operations, and
Vehicle procurement met to determine what the maximum grade for the system could be. The
mainline Silver Line tunnel is designed to accommodate not only the Bus Rapid Transit (BRT)
vehicle to be used on the Silver Line but also to accommodate the potential future conversion to
light rail. For design purposes the MBTA assumed that the Green Line Number 8 vehicle would
be the prototype for any future light rail system. This is represented in the fleet by the Breda LowFloor vehicle.
After review and examination by the MBTA staff, the MBTA determined in 1993 that the preferred
maximum grade for the Silver Line would be 5%, though the MBTA would allow the design team
an absolute maximum grade of 6% with specific permission which has been granted in rare
circumstances. This preferred maximum has been waived in only two locations. First, a 5.6%
gradient is allowed in the vicinity of the I-93 tunnel. This waiver was granted as part of the
conceptual design of the Full Build alignment, since the Silver Line has a short distance to dive
down under the South Bound Central Artery tunnel from Atlantic Avenue where it sits on top of
the North Bound Central Artery tunnel. Second, a grade of 5.7% is allowed in the area to the east
of World Trade Center at the portal so that the vehicle could leave WTC station and rise up to
meet D Street. No other variances have been allowed. In fact the MBTA went to great lengths to
avoid steep grades on Phase II, particularly when they are in conjunction with tight radius turns
even though this meant redesign of a portion of the project. For example, the Russia Wharf
Buildings were underpinned and the tunnel realigned at additional cost so as to avoid what the
MBTA and FTA jointly believed to be an unsafe and unacceptable condition. The original
alignment, which was constrained by the Central Artery project, made a 90-degree turn from the
Atlantic Avenue ROW through the CA/T Vent Building No. 3 and descended a grade in excess of
5% under the Fort Point Channel. The final alignment that was built makes a flatter turn and
passes under the Russia Wharf complex and the Fort Point Channel at a 3% grade.
Other geometric standards also apply to this tunnel. A light rail system requires a level (or at a
maximum 0.5% grade) in a tangent section of track for track turnouts for merge/diverge points.
Stations are preferred to be 0.5% but can go to grades as high as 2%. Additionally, a minimum
turning radius of 100 feet is preferred with a minimum allowable radius of 50 feet.
The Mid-Block Alternative results in a grade of 6.4% along Tremont Street between the portal at
the New England Medical Center (NEMC) and Boylston Street. The MBTA’s current planning
assumes that future light rail expansion/connection to the Back Bay would occur along Boylston
Street west of Tremont Street. But if instead that connection were to occur via Stuart Street,
which would be required under the Mid-Block Alternative, the grade would rise to 8.2%. Both of
these grades exceed the MBTA’s maximum grade of 5%.
Many commenters stated that they believe the grade restriction is self-imposed by the MBTA and
that if removed, the Mid-Block Alternative would be viable. Commenters also identified other
cities with actual grades steeper than the MBTA’s criteria. It is generally accepted throughout the
2
industry that grades should be minimized whenever possible to ensure safe and efficient
operation of the system. In fact, recent literature recommends a maximum grade of 4%. Still
locations exist nationally where there is no option but to increase the grade. Pittsburgh for
example has a grade of over 7% in the new North Shore Connector light rail line due to the fact
that the tunnel dives under the river and then must rise to go up the hills on the banks of the river.
While clearly these examples exist, they tend to exist in situations where there is no option but to
increase the grade since certain natural or man-made obstacles occur that limit options and
dictate a specific grade. These situations tend to be the rare exception and generally occur when
there is no feasible option to do otherwise.
Additionally, commenters have stated that it is unnecessary to design the project to
accommodate light rail, since light rail would be in the distant future, and when light rail is ever
built, the light rail vehicles at that time may be able to accommodate a steeper grade. According
to these commenters, if the Silver Line is designed to accommodate buses only, the grade
standards could be relaxed. The MBTA feels strongly, however, that it is important to design the
system so as to not preclude light rail today, and that it is imprudent to design the system
predicated on an assumption that the vehicles in the future may have abilities that today’s
vehicles do not. As a result, the MBTA will be designing the system so as to not preclude future
rail conversion using today’s standards for that conversion. In fact, the higher grade would
preclude not only future conditions, but may also preclude current conditions, since the NeoPlan
60’articualted vehicle which is soon to come into service for Silver Line Phase II, and is the
vehicle to be used on Silver Line Phase III, is grade-constrained at 6% (max) per vehicle specs.
2. Station Functionality and Transit Operations
One of the major determinants for a transit station or system is its ability to function under the
planned or projected service plan. By having one station as opposed to two stations, the single
Silver Line platform is on average further away from downtown origins and destinations and also
further away from the existing Green and Orange Lines. For this reason, access time from the
street level and transfer time from the Green and Orange Lines to the Silver Line Mid-Block
station platform is less efficient for the passenger. This represents a disincentive to using the
system and as such, results in fewer riders switching over to the Silver Line.
Access Time: When forecasting travel demand, several factors come into consideration. The
most significant of these is passenger transfer time and vehicle travel time, headways (the
average time between vehicles). The longer each or any of these factors is, the greater the
impact on the ridership. As noted above, because a single station will be on average further
away from a group of trip origins and destinations than will two stations, access time to the MidBlock Alternative station will increase the overall passenger travel time, which in turn makes the
trip less attractive and reduces ridership. Many people perceive the location of the station as the
location where they enter the station (i.e., the headhouse). Rather, the location of the station is
actually at the platform level, where the passenger boards the Silver Line vehicle. To measure
the distance between an origin and the Silver Line, the ridership model identifies a series of
points (known as centroids) along the streetscape that represent typical or average points where
a passenger would begin his/her walk to the station. In order to forecast ridership with a travel
demand model, ‘centroids’ need to be connected to platforms. Given that the Mid-Block platforms
are so much further from the centroid points than they would be in the Two-Station Alternative,
the access for the travel is more difficult, which again is reflected into the reduced ridership.
Passenger Transfer Times:
Transfer is another particularly important factor; the longer it
takes to transfer or the more cumbersome that transfer is, the less likely a person is to make the
trip and as such, the ridership goes down.
More important than the actual transfer time is the level and complexity of transfer as a result of
the station architecture. The Two Station Alternative includes stations underneath or physically
adjacent to the existing Orange Line Chinatown & Green Line Boylston. As such, the transfer
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connections occur in vertically organized circulation zones within multi-volume spaces, conditions
that orientate the passengers and provide them with visual clues about their destination.
Passengers move up or down in escalators banks located next to each other and in sight of their
destination. In the Mid-block alternative, however, the rider is required to make use of long
horizontal pedestrian tunnels to transfer. As a result, the quality and degree of difficulty of the
transfer in the Mid-Block alternative is inferior, which has a direct bearing on the rider.
Many commenters have expressed a disbelief that riders would find such a transfer objectionable,
especially considering that there are similar transfers in other places in the MBTA or in other
transit systems. The key issue is not that people would not be willing to make such a transfer if
the system is built that way, but will they make the transfer if they have a faster or shorter
alternative. Consider a passenger coming from the west on the Green Line and headed for the
Boston Convention and Exhibition Center. In the Mid-Block Alternative, that passenger’s total
travel time, including the transfer, is actually longer than simply continuing on the Green Line to
Park Street, switching to the Red Line to South Station and then switching to the Silver Line to the
waterfront. These are key markets since a major and original purpose of the Silver Line was to
alleviate capacity on the Green Line. If the Silver Line cannot capture this rider and provide a
transportation benefit, then the utility of the project is reduced -- the transportation benefit is
lessened. Given that the transportation benefit is such a key consideration for FTA when
deciding whether or not to fund the project, this factor is extremely important.
As a solution, many commenters suggested that the MBTA install escalators, elevators and
moving sidewalks to make the transfer faster. Any alternative would include escalators and
elevators. A moving sidewalk, however, does not make the transfer faster. The transfer times in
the assumed that the passenger is walking an average speed of 250 feet per minute (fpm) for the
horizontal and 45 fpm vertically using an escalator. A moving sidewalk has an average speed of
90 to 120 feet per minute. The safety codes under certain conditions allow a 12-degree incline
and speeds up to 180 feet per minute.1 For example, the moving sidewalks at Logan Airport
between Central Parking and the terminals are designed to operate in conformance to these
standards. While a passenger can increase travel speed by walking on a moving sidewalk,
walking is generally not much faster than 250 feet per minute. For the moving sidewalk to make
a substantial difference in the resulting ridership projections, the MBTA would need to assume in
the travel demand forecasting assumptions that every passenger walks rather than stands on the
moving sidewalk. Additionally, the MBTA would need to assume that every passenger walk on
the sidewalk at a fairly fast pace. These two assumptions are necessary to develop a transfer
time that is measurably shorter than what the MBTA had previously assumed. The MBTA
believes that it is highly unlikely that the FTA would allow the MBTA to make these assumptions
in the travel demand forecast model.
Additional pedestrian tunnel width would be required to accommodate passengers opting not to
utilize the moving sidewalk and for periods when the moving sidewalk is taken out of service for
repairs. The additional costs of this tunnel have not been calculated but would need to be if this
option were to be pursued. These capital costs would likely have a negative effect on cost
effectiveness. (See below)
While any of these issues could appear to be negligible, when taken as a composite, the result is
an overall passenger experience that takes longer is more cumbersome and ultimately results in
fewer passengers and lower user benefits.
Vehicle Dwell Times and Station Capacity
Either alternative (Two-Station or Mid-Block) are proposed to serve the same passenger
‘catchment area’. In a Two-Station Alternative two platforms are furnished (one at Chinatown;
one at Boylston) providing a total of six bus berths per direction. The Mid-Block Station, on the
other hand, provides a single three-berth platform per direction to service essentially the same
1
Architectural Graphic Standards (6th Edition) and Massachusetts State Building Code (6th Edition)
4
peak-period passenger volume. This fundamental difference is critical to understanding the
operational issue surrounding the Mid-Block Station.
The passenger demand at the Mid-Block station is higher at this single location, than at either of
the stations in a Two-Station Alternative and results in a longer estimated vehicle dwell time
(Table 1). The longer dwell time needed to accommodate passenger boarding and alighting
translates into a longer travel time and reduced ridership, if dwell time were the only variable.
The critical issue in this scenario is the relationship of dwell time and vehicle headways. In the
Mid-Block Alternative the dwell times exceed headway. Headways cannot be maintained
resulting in unacceptable vehicle queues throughout the system.
Table 1. Maximum Station Dwell Times vs. Effective Headway (AM Peak Period,
Eastbound)
Station
Boylston
Chinatown
Mid-Block
Dwell Time +
Clearance Time
34 sec
52 sec
66 sec
Effective
Headway
49 sec
49 sec
49 sec
The table shows that vehicles at the Mid-Block station dwell for 66 seconds on average to
accommodate passenger boarding and alighting in the peak eastbound direction during the AM
peak period.
Table 3 summarizes the vehicle capacity for each station for these dwell times in the eastbound
AM peak. The vehicle capacity is defined as the number of vehicles that can be served at each
of these stations per hour. As the table shows, combining the Boylston and Chinatown Stations
into one Mid-Block station reduces the vehicle capacity significantly, to approximately 88 vehicles
per hour.
Table 3. Station Vehicle Capacity (AM Peak Period, Eastbound)
Station
Boylston
Chinatown
Mid-Block
Vehicle Capacity
[veh/hr]
163
135
88
Service Plan (74 veh/hr)
as % of Vehicle Capacity
45%
55%
84%
The reduced vehicle capacity indicates an increased propensity for vehicle queuing and service
delays due to normal variations in vehicle dwell time because the system is operating closer to its
theoretical maximum capacity. Like any congested transportation network, increasingly small
variations in vehicle capacity will cause queuing and service degradation when operating under
these conditions. Simply stated, there is less room for error.
While the Mid-Block station theoretically has sufficient vehicle capacity to accommodate the peak
hour service plan, its lower vehicle capacity indicates that this alignment is more susceptible to
service disruptions and delays due to anticipated variations in passenger demand, headway, and
dwell time as compared to the Two-Station Alternative. This phenomenon is similar to what can
be seen every day at Park Street on the Green Line. Even though Arlington Station handles the
same number of trains per hour as Park Street, because of the unusually high number of
boardings at Park Street, congestion is significant, notwithstanding the 4-track capacity, while
Arlington is not a bottleneck. The Silver Line is intended in part to decongest Park Street by
attracting some of those transfers. The Mid-Block creates a Park Street-like bottleneck on the
Silver Line.
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Cost and Cost Effectiveness
Cost: During the public review, several of the commenters indicated that a Mid-Block Alternative
would cost substantially less than an alternative with two stations. This is not the case. The MidBlock Alternative has a capital cost nearly identical to the Two-Station Alternatives, due the
additional elements associated with the station design and the turn around loop.
Station Design: In the Mid-Block Alternative, the station would be located within a narrow
section of Boylston Street, and the station would need to be wider than the right-of–way
encroaching on private property most of its length. This is in contrast to the two separate
stations, which would fit within the right-of-way with only a few exceptions. Since more
passengers would be using the one station (as opposed to two stations) the Mid-Block station
must actually be wider and longer than either of the two stations so as to accommodate
passenger flow and provide safe egress. Both of these issues combine to make the Mid-Block
Station bigger than either of the two stations in the Two-Station Alternatives. To accomplish this,
the MBTA would need to underpin abutting buildings, some of which are significant historic
structures (e.g., the Masonic Temple, the Young Men’s Christian Union). Real estate acquisition
costs and Building mitigation cost including liabilities associated with it are substantially greater
than in the Two-Station Alternatives and are subject to greater risk of increase over time.
Turn Around Loop: In order to provide service that provides transit to the maximum number of
people, the MBTA believes that an underground loop is critical to the operation of the Silver Line.
Over 70% of outbound vehicles are returned via the loop so as to accommodate the riders who
will use the Silver Line to make trips that begin or end between Boylston Station and the South
Boston Waterfront area. As such, it is important to optimize the use of the vehicle fleet, deploying
them to trips that will serve the core tunnel segment by turning some of the vehicles around at
Boylston and going back to the Waterfront area (as opposed to the rest of the vehicles which
would go on to Dudley or the Back Bay). This underground loop provides the flexibility and the
control to provide high quality and reliable service in the core tunnel segment where the largest
ridership occurs.
A loop at Boylston Street and Charles Street is not practical with the Mid-Block Alternative. As a
result, a different location for the loop has been identified. Several commenters from the
community have suggested the existing parking lot on the southwest corner of Tremont and
Stuart Streets across from the Wang Center. This property, however, is the site of the future
Loews Hotel. The MBTA has met with the developer of the hotel to discuss the feasibility of such
a proposal. The developer of the hotel has already been through the Boston Redevelopment
Authority process and received approval for the project and is currently working on the financing
to begin construction. Adding a loop at this location would require increasing the already
excessive grade and would entail merging turn back vehicles with a steep downgrade of over 6%,
a highly undesirable operation.
The Loews project includes two levels below ground providing for a mechanized parking garage
as well as hotel services such as laundry, kitchen and mechanical rooms. Building the loop on
the site at the necessary elevations would require the developer to allow the MBTA to occupy
space planned for hotel uses. The two floors of the hotel space would be relocated below the
loop. While any Joint Development Agreement will be the subject of negotiation and the outcome
is unknown at this time it can be assumed that the MBTA would be required to compensate the
developer the additional construction cost, as well as the real estate costs for the permanent land
easement for the loop and long-term impacts to the hotel operation. It is estimated that codevelopment construction costs and the right of way/easement costs are estimated to be
approximately $47 million.
With each of these needed elements, the cost of the Phase III project would be $748 million,
which is comparable to the cost of the Two-Station Alternatives (all are within a range of 5% $748
to $780 million).
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It is possible to build the alternative without a loop and thus avoid some of these added costs.
The Mid-Block Alternative without a loop would cost $690 million. While this is a less expensive
option, it also results in a substantially inferior and undesirable service plan. Vehicles that would
normally turn back to the waterfront area via the loop (56 out of 74 per hour during the peak
periods) are now required to exit the portal, turn around on a circuitous route on a congested
surface street network, and then re-enter the portal. Additionally, instead of 18 vehicles per hour
exiting the tunnel (and the same number entering the tunnel) there would now be 74 vehicles per
hour adding significant levels of traffic to the local street network. Depending on the surface loop
route selected and agreed to by the City and other stakeholders the fleet requirement would
increase by as many as 19 vehicles at a cost of approximately $1.6 million per vehicle. Similarly,
the incremental operating costs of this option would increase by as much as $2.9 million per year.
For the purpose of this analysis, the MBTA has assumed that the roadway network in and around
NEMC could accommodate 74 vehicles per hour. This is a very generous assumption and further
traffic analysis is likely to show that this type of service plan would have a significant effect on
day-to-day traffic as well as the emergency access to the hospital.
FTA Cost Effectiveness
Measures of cost effectiveness quantify the costs of an investment in relation to anticipated
benefits resulting from the investment. Such measures help decision makers compare the
relative value of alternative investment options – in this case, among Silver Line Phase III transit
alternatives.
As part of its New Starts program, which provides funding to major transit projects like the Silver
Line through a national competitive application process, the FTA dictates that a particular
methodology be followed to calculate cost effectiveness. There are three basic inputs to FTA’s
calculation:
•
Capital costs, meaning the costs associated with designing and constructing the project;
•
Operating and maintenance costs, which are the ongoing costs of running the service
once the project is constructed; and
•
Transportation system user benefits, which refer to the hours of travel time savings that
will be enjoyed by transit riders on the entire MBTA system once the project is up and
running.
Each of these inputs is described in more detail below.
Capital Costs
The engineering industry uses standard methods for estimating transportation project capital
costs, based on the types of construction activities that will be undertaken and on local costs for
constructing similar projects. For the purposes of calculating cost effectiveness, Silver Line
capital costs are first estimated in current year dollars. These costs are then converted into
annualized costs, taking into account the lifecycle or replacement schedule of major project
elements. FTA provides standard lifecycle factors for translating these costs into an annualized
amount that reflects assumptions about the anticipated life expectancy of each major project
element. FTA developed these annualization factors through research on the typical lifecycles of
such project elements as tunnels, stations, power and communication systems, and vehicles.
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Operating and Maintenance Costs
The annual cost of operating and maintaining the Phase III service is estimated, based on a
recommended methodology developed by FTA. This methodology, which reflects the MBTA’s
operating costs for comparable services, accounts for all the resources needed to operate and
maintain the service, such as wages and fringe benefits for drivers, maintenance, and
administrative staff, the cost of purchasing fuel, etc. For the purposes of calculating cost
effectiveness, the annual Silver Line operating and maintenance (O&M) cost is calculated in
current dollars.
Transportation System User Benefits
A key purpose of implementing a new transit project is to improve the service and benefits
provided to transit customers. There are many ways to express those benefits which may extend
beyond the transit project itself, including reduced congestion on area roadways and associated
improvements in air quality. For its calculation of cost effectiveness, FTA has developed a
standardized methodology for expressing benefits in terms of hours of travel time savings. These
savings, which come directly from the regional travel demand-forecasting model, encompass both
the hours of travel time saved by riders on Silver Line as well as travel time savings for transit
riders using other MBTA services. For example, riders on the existing Phase I service would be
expected to receive a travel time savings for trips to South Station, the Waterfront area, and
Logan Airport once Phase III is implemented, since their overall travel time is reduced. While
there are many methods for calculating cost effectiveness, the MBTA utilizes the methodology
required by the FTA for its New Starts funding program to ensure consistent measurement of cost
effectiveness results for all transit projects across the country.
Calculation of Cost Effectiveness
As shown below, the calculation of cost effectiveness divides the annual capital and O&M cost of
each Phase III alternative by the annual user benefits measured in terms of hours of travel time
savings:
Cost Effectiveness
=
Annual
Capital
+
O&M
Annual Hours of Travel Time Savings
Costs
The result of this calculation is the cost per hour of travel time savings. The lower the cost
effectiveness result, the better the value generated by an alternative.
The FTA has established guidelines to rank projects on their relative cost effectiveness, with each
range of costs given a certain rating. The following is FTA’s system for rating a project’s cost
effectiveness:
High
Medium High
Medium
Low Medium
Low
$9.99 and under
$10 – $12.99
$13 -- $19.99
$20 -- $24.99
over $25
FTA has also determined that it will not consider for funding any project whose cost effectiveness
ratio is rated “Low,” that is, a project with a cost effectiveness of over $25. The following table
compares the costs and the cost effectiveness of each of the Mid-Block Alternatives considered
as well as the three other Phase III alternatives currently under consideration by the MBTA:
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Alternative
Total Cost2
Ridership4
$689.6
Annual
O&M3
$7.8
132,000
User
Benefit5
2,822,560
Mid Block /
No Loop
Mid Block/
Loews Loop
Tremont
Street/
NEMC Street
Charles/NEMC
$748.0
$6.4
132,000
2,822,560
$780.6
$8.2
162,000
3,984,565
$751.1
$8.2
162,000
3,984,565
Cost
Effectiveness6
$20.16
(Low Medium)
$20.79
(Low Medium)
$15.55
(Medium)
$14.89
(Medium)
The ridership of the Mid-block alternative is approximately 83% the ridership of the Tremont
Street and Charles Street Alternatives, which both portal at NEMC. For the Mid-Block Alternative
the user benefit, which is the best metric for determining overall transit benefit, is 70% of NEMC
Portal. Both Mid-Block options (Loop/No Loop) result in a cost effectiveness ratio that receives a
“Low Medium” ranking. Because cost effectiveness represents 50% of the weighted value of the
Project Justification, the MBTA believes that a “Low Medium” cost effectiveness ratio would harm
FTA’s recommendations to Congress on future funding for Phase III, given the intense national
competition for these funds. A copy of the FTA guidance on ranking can be found on the FTA
website at located at www.fta.dot.gov/documents/Appendix_D.pdf
Conclusion:
The Mid-Block Alternative cannot be built unless the MBTA discards its long held design and
engineering standards in regard to maximum grade. While there are other transit properties that
have grades in excess of the MBTA’s and even in excess of the Mid-Block grade, these situations
exist only when there is no feasible alternative such as when an immovable object (e.g., a river or
an underground tunnel) prevents the designers from achieving the preferable lower grades. It is
a well-accepted objective in the engineering and transit industry to minimize grades to the
greatest extent feasible or practicable, given the relationship that excess grades have to
increased cost, increased operating costs and increased wear and tear on vehicles.
Even if the MBTA were willing to put aside its longstanding design and engineering standards, the
Mid-Block Alternative would fail for other reasons. While it seems reasonable to conclude that
the Mid-Block Alternative would result in the same transportation benefits for lower cost, further
examination demonstrates this to be incorrect. The Mid-Block Alternative neither provides the
level of transportation benefit nor the ridership that can be provided from an alternative with
stations at both Boylston and Chinatown. This reduction in ridership as well as in transportation
benefits results because the Mid-Block Alternative would degrade the service level through longer
2
Capital Costs is measured in the total cost of the project in Year of Expenditure (YOE) Dollars.
The CE calculation takes this number and annualizes the cost in current year dollars.
3
Annual Operation and Maintenance costs are measured in current year dollars (in millions).
4
Ridership is measured in total riders per average weekday
5
User Benefit is measured in hours of transportation user benefit per year as calculated by
SUMMIT, a travel demand forecasting software created by the FTA and required by Congress to be used
on all New Starts projects.
6
Cost Effectiveness is measured in dollars per hour of travel time savings.
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access times, more cumbersome transfers, and higher station dwell times, making the overall
service measurably less attractive than the Two-Station Alternatives. The ridership forecasting
bears this out, and the methodology used to demonstrate this phenomenon is the methodology
approved by the FTA.
The construction cost of a Mid-block station is not half the cost of two stations as many have
assumed, since the Mid-Block Station would require a larger envelope for the station resulting in
underpinning of abutting structures. The cost of the Mid-block Alternative is approximately the
same cost of the alternatives with two stations. This alternative, however, results to a drop in
ridership and user benefit thus giving the Mid-Block alternative a poor cost effectiveness ratio.
As a result of these (and several other factors) the MBTA has determined that the Mid-Block
Alternative, both with or without an underground loop, is not a prudent nor feasible alternative and
is therefore not be carried forward for further consideration.
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