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.
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