Study: I-81 tunnel option could cost up to $4 billion, take up to 10 years to build

Dec 4, 2017

Updated at 2:30p.m. Monday

The state Department of Transportation released a long-awaited study Monday on the feasibility of replacing the aging elevated section of I-81 that runs through downtown Syracuse with a tunnel or depressed highway. 

According to the study, seven options for a tunnel were explored with four deemed feasible. 

  • The first option would be aligned southwest of downtown Syracuse, connecting into West Street close to the interchange with I-690.  This ten-year, $4.5 billion project would minimize disruption to interstate traffic during construction, maintain connectivity between I-81 and I-690, while facilitating future reconstruction of the I-690 viaduct.  This 2.6 mile option would require 42 parcel acquisitions.

  • The second option would be generally aligned west of the existing I-81 viaduct, along South Townsend Street.  This nine-year, $3.3 billion project would minimize construction complexity and risk by mining under I-690 without a direct interstate-to-interstate connection.  The project would not reconstruct the I-81/I-690 interchange.  This 2.2 mile option would require 30 parcel acquisitions.

  • The third option would be aligned immediately east of the I-81 viaduct.  This nine-year, $3 billion project would be aligned immediately east of the I-81 viaduct, maintaining connectivity between I-81 and I-690, maximizing the use of the existing I-690 infrastructure while minimizing easements required outside of the public right of way. This 1.2 mile option would require six parcel acquisitions.

  • The report concludes that the best tunnel option is one aligned immediately west of the I-81 viaduct while maintaining connectivity between I-81 and I-690.  This nine-year, $3.6 billion option would also reconstruct and improve the I-690 viaduct.  At 1.6 miles in length, this project would also require 22 parcel acquisitions.

Two options for a depressed highway were considered, but deemed not feasible because "both options would have resulted in the permanent closure of multiple city streets; a permanent division of the City of Syracuse; unnecessary traffic caused by construction; several technical challenges including buoyancy, foundations and utilities; and costs between $3 and $4 billion over a seven to ten-year period," the study said.

Syracuse Mayor Stephanie Miner released a statement Monday afternoon saying "a tunnel is not feasible financially and would have detrimental impacts on the economic and social health of our community." Miner also called on the state DOT to remove the tunnel from consideration and consider options that "focus on connecting the street grid, opening up more land for potential development, and improving the quality of life of Syracuse residents."

The study, conducted by engineering consultant WSP, was ordered by Gov. Andrew Cuomo to look at the feasibility of a tunnel or depressed highway, after the DOT rejected the option. 

Other options for the elevated section of I-81 include rebuilding the viaduct or a street-level grid. The Department of Transportation will review the study and make a determination on how to proceed "in the coming weeks."