More than 20 years ago Sound Transit “decreed” that light rail was the answer for cross-lake mass transit. They may or may not have been aware of the fact light rail has never been installed on a floating bridge.
In September of 2005 the WSDOT attempted to demonstrate the I-90 Bridge could withstand the loads using flat bed trucks to simulate the 74-ton light rail cars. The WSDOT concluded “results of the test confirmed previous findings that the bridge can be structurally retrofitted to carry the loads associated with the light rail system under consideration, in addition to general traffic on the roadway”.
Apparently the Washington Sate Legislature Joint Transportation Committee (JTC) was not satisfied with WSDOT tests because they commissioned an independent review team (IRT) to evaluate the bridge design with light rail. The results of the IRT evaluation were documented in the “I-90 Homer Hadley Floating Bridge Independent Review Team Light Rail Train Impacts, Final Report, Sept 2008”. It includes the following “Conclusion”:
Based on extensive study, analysis, and discussions with Sound Transit and WSDOT the IRT has concluded that all issues associated with the installation of LRT on the Homer Hadley floating Bridge and approach spans can be addressed or mitigated providing that the IRT resolutions and recommendation are incorporated.
However, several issues could affect project cost estimates and schedules and therefore should be resolved at the earliest states of the project design. One issue deals with a required design element (LRT Expansion Joint Tract Bridge) has no history of use on floating bridges, and therefore requires careful study and testing in the early stages of the project.
Since many of the issues require additional study, analysis, and design the IRT recommends that an independent review or peer review panel be organized to provide oversight throughout the LRT East Link design process.
One would have thought the JTC would have used their WSDOT oversight responsibility to insist on additional testing. Instead three months later the December 2008 Draft Environmental Impact Statement (DEIS) included the following:
The Washington State Legislature Joint Transportation Committee commissioned an independent review team (IRT) to evaluate the bridge design with light rail. The IRT concluded that all issues identified as potentially affecting feasibility can be addressed.
The DEIS simply “neglected” to mention the IRT concerns. The U.S. Department of Transportation Federal Highway Administration had similar concerns. Paragraph 5 of a February 25, 2009 letter, HRW-WA/WA624 responding to Sound Transits 2008 DEIS for the East Link Project included the following:
“We do not agree that there has been enough work done to justify the conclusion that it is feasible to design a light rail track system to accommodate the movements of the I-90 floating bridge” and “there is additional work to be done to determine if it is feasible to design an expansion joint to accommodate light rail”.
Again, one would have thought the FHWA concerns (and IRT concerns) would have convinced the JTC to insist on early testing to verify bridge compatibility with light rail. Instead nearly three years later the July 2011 Final Environmental Impact Statement (FEIS) includes exactly the same response to concerns as the 2008 DEIS. The JRT apparently acquiesced to this lack of response.
Finally, five years after the IRT recommended “careful study and testing in the early stages of the project”, WSDOT/ST decided to test whether light rail can be installed on a floating bridge. In August they began tests at the Transportation Technology Center in Pueblo, Colo. The testing will apparently continue through the end of the year.
Even if this “better late than never” testing confirms new “expansion joints” will allow four car trains simple mathematics belies ST claim of up to 24,000 riders an hour. The JTC refused to recognize that light rail will never have the capacity or the accessibility required for cross-lake mass transit. That along with their refusal to use their oversight to insist the WSDOT/ST consider BRT for the bridge center roadway is a major contributor to our current transportation funding problems.