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Cedar Street is the preferred alignment

Noise and vibration impacts have been studied and can be mitigated.

Cedar Street alignment for LRT was selected in the early 1990s and its selection was reaffirmed in 2001 Scoping Summary Report (pdf) and Appendix (pdf). Cedar Street was selected as the preferred alignment because it: 

• Serves the core of downtown businesses 
• Has a wide bridge crossing the I-94/35 commons
• Carries slightly less traffic than other parallel north-south streets of Minnesota, Wabasha, Robert or Jackson
• Is NOT a major access route into downtown like Wabasha, Robert and Jackson
• Has minimal property access impact issues as compared to other north-south streets
• Avoids directly impacting vehicle access to Wells Fargo Tower ramp and loading dock, the largest Class A office space in downtown with an east side of Cedar Street alignment
• Can accommodate both pairs of tracks rather than a need for two streets to accommodate one pair of track each
  

See additional information from the City of St. Paul on the history of the Cedar Street alignment and rationale for its selection (pdf).

Federal guidelines followed in identification of mitigation strategies

Extensive testing following Federal Transit Administration (FTA) guidelines (pdf) shows vibration and noise impacts from Central Corridor LRT vehicles can be mitigated at MPR. See listing of Cedar Street noise and vibration reports and articles.

The FTA requires that noise and vibration issues be addressed through the federal environmental review process and documented in the Draft Environmental Impact Statement (DEIS) and Final Environmental Impact Statement (FEIS). The FTA requires the DEIS to include a general impact assessment of the alignment and the FEIS to identify specific impacts by receptor property and noise sensitivity category as well as document mitigation measures for moderate or severe impacts.

As our experienced project engineers, who have worked on other LRT projects around the country, have discussed with MPR management, mitigation measures could include soundproofing their studios, installing a floating concrete slab or equivalent under the track bed to attenuate the vibration caused by LRT and adjusting the use of train horns. 

Noise and vibration impacts have been studied

In 2003, MPR completed an analysis of potential vibration impacts from light rail as part of planning for construction of their facility expansion.  MPR commissioned this study after the Cedar Street alignment was reaffirmed in 2001 and after MPR had secured millions of dollars of financial assistance from the City of St. Paul and foundations.

In May 2006, Ramsey County published an Alternatives Analysis/Draft Environmental Impact Statement that included a section on noise and vibration impacts (pdf) and a technical report on noise and vibration impact (pdf).  

In June 2006, the Metropolitan Council became the project lead and in December 2006 received permission from the FTA to enter into Preliminary Engineering.  Starting in 2007, the Central Corridor Project Office began addressing issues that were raised in the DEIS, including noise and vibration impacts.
   
July 2008 the Central Corridor Project Office prepared a draft technical memorandum that summarized results from detailed vibration testing along Cedar Street.  The project office shared the draft memorandum with MPR and the adjacent churches.

In August 2008, the FTA and Met Council published the SDEIS which summarized noise and vibration impacts (pdf)  The SDEIS was not intended to duplicate the analysis conducted in the DEIS, rather the purpose was to analyze key changes that were not documented in the DEIS.

In October 2008, the Met Council conducted a simulation of noise resulting from LRT bells and horns and prepared a technical report (pdf), which was shared with MPR. 

In September through October 2008, supplemental testing was conducted to address stakeholder concerns.  The final report was published in December 2008 and again shared with MPR and the adjacent churches. See the CCLRT Vibration Analysis Executive Summary or the complete Vibration Analysis report - Part A | Part B.