FMCB Receives Preview of North South Rail Link Feasibility Reassessment Draft

Today the MBTA’s Fiscal and Management Control Board (FMCB) received a preview of the general findings of the North South Rail Link (NSRL) Feasibility Reassessment, which included findings in the areas of infrastructure, ridership, costs, and potential benefits. The draft NSRL Feasibility Reassessment report is still pending.

In 2016, the Baker-Polito Administration committed to conducting a reassessment of the feasibility of the NSRL, which was first analyzed in the late-1990s/early 2000s through an environmental review process. Work in this regard began on July 1, 2017, by global design and consulting firm Arup, who conducted this analysis with a project scope that included identifying changes in demographics and technology since the last concept in 2003; identifying a viable alignment; estimating project costs; summarizing benefits in ridership, changes in vehicle miles travelled, air quality improvements, and development opportunities in the project corridor; and including frequent coordination with the NSRL Working Group. This project scope was designed to understand the high-level costs and benefits of NSRL relative to not pursuing the NSRL (“No Build”) or expanding South Station.

The feasibility of the NSRL from the perspective of infrastructure was found to depend largely on tunnel and station depths. Station depths of 115 and 195 feet—deeper than the Red Line's Porter Square Station, the MBTA's current deepest station—would be required.

Additionally, construction of the Back Bay portal would prevent any trains from accessing South Station from the west and most from accessing it from the south (other than the Fairmount and Old Colony Lines) during the roughly 2-year construction phase of the portal. This means the termination of Worcester Line service west of Back Bay and the potential rerouting of Amtrak Northeast Corridor, Franklin Line, and Providence Line service via the Fairmount Line for 2 years.

All NSRL station platforms would also be underground and would maintain current connections into today’s South Station headhouse (Red and Silver Lines) and North Station subway (Green and Orange Lines). All northside service was also assumed to run through the NSRL tunnel, meaning that surface-level tracks and platforms would not be required for revenue service.

The reassessment study also explored the concept of shifting the Commuter Rail portion of North Station south by 4 blocks, preserving the Green/Orange Line connection (though at Haymarket Station), and creating a new direct connection to the Blue Line at State Station (obviating the need for a costly third station as envisioned in the 1995-2003 analysis).

Ridership projections were made for 4 different service alternatives agreed to with the NSRL Working Group. These included:

NSRL Regular Service (2-track), which maximized service during the peak and hourly off-peak service (estimated ridership of 195,000)
NSRL All-Day Peak Service (2-track) with maximum service throughout the service day (estimated ridership of 225,000)
NSRL All-Day Peak Service (4-track) with maximum service throughout the service day (estimated ridership of 250,000)
South Station Expansion All-Day Peak Service (not including the NSRL) with maximum service throughout the service day (estimated ridership of 195,000)

The estimated ridership of the “No Build” option is 150,000. Unlike typical ridership modeling, all service plans assumed no constraints on station parking.

The assessment also considered costs associated with NSRL. Total costs, including all costs associated with the tunnel construction, new or additional locomotives or coaches, upstream improvements needed to support increased service levels, and risk contingencies, range from $12.3 billion to $14.4 billion for the 2-track alignments and $21.5 billion for the 4-track alignment.

All project costs were escalated to the presumed midpoint of the construction year (2028). Arup estimated the cost of SSX in 2018 dollars as $1.75 billion (when only looking at similar project elements as the MassDOT SSX process), which is within 5 percent of the estimates conducted by VJ Associates (for the SSX project) and Keville (from an independent MBTA cost estimate). The same cost estimate, assuming rolling stock to support aggressive service levels and associated upstream improvements, for SSX were projected at $4.7 billion (2028 dollars). The project assumed the electrification of just the tunnel to the first station on each line, which was agreed to within the project scope, so as not to burden the NSRL cost with full electrification. This results in the procurement of dual-mode locomotives to replace much of the existing fleet.

Also noteworthy is that NSRL tunnel costs were in line with cost estimates that were done as part of the 1995-2003 work when estimated to 2028. Additionally, prior assumptions about operating cost savings resulting from reduced deadheading due to through-running trains and better access to BET were not supported by Arup’s analysis, which found that current MBTA operations include such a small share of non-revenue miles (3 percent of total miles) that the opportunities for savings were relatively small and overwhelmed by the increase in operating costs to support the more aggressive service levels modeled.

Potential benefits of NSRL include increased capacity by 25 percent (in terms of the number of commuter rail seats that arrive in Downtown Boston during the peak period). NSRL could also allow for a larger and less complicated development opportunity at South Station, eliminates the need for a close-in layover at Widett Circle, and could create the potential for redevelopment at the site of today’s surface tacks and platforms behind TD Garden. Environmental benefits were mixed – while all alternatives resulted in reductions in vehicle miles travelled and automobile emissions, the use of dual-mode locomotives combined with the significant increase in service resulted in little or no air quality benefit.

Next steps regarding the NSRL reassessment include the presentation of these findings at a public meeting to be held on June 21 at 5:30 PM in Boston at 10 Park Plaza. Following this public meeting, the draft NSRL Feasibility Reassessment will be released in early July 2018 with a public comment period in July and August. The final NSRL Feasibility Reassessment Report will be released in early fall 2018 with ongoing examination of electrification and alternative service models through the MBTA’s Rail Vision Study.