I-90/Light Rail Compatibility Test Status?

I periodically get an E-Newsletter from Sound Transit about their progress in designing the various segments of the East Link light rail program.  It references an East Link document archive that lists more than 30 status reports since March, primarily dealing with “Kickoff to final design” for the different segments.  Sound Transit is obviously spending a great deal of time and money in planning for the Bellevue East Link segments and informing the public about how their design is progressing.

However, very little has been said about their progress on the I-90 bridge segment.  All the time and money spent on the Bellevue segments will be wasted unless Sound Transit can convince the FHWA that the I-90 Bridge can support light rail.  East Link is the first attempt to install light rail on a “floating bridge”.  The problem is assuring the durability of the 190 ft connections between the fixed and floating portions at each end of the bridge. 

The original connections have already needed replacement under far less severe conditions than what could be expect with four 74-ton-car trains traveling in each direction.  The fact light rail operation would result in nearly 600 tons of weight on the south 1/3 of the bridge where the two trains cross would seem to exacerbate the connection design problem.

An earlier post (10/01/13) explains how Washington State Joint Transportation Committee (JTC) concerns led them to commission an independent review team that concluded in a Sept 2008 report, as did the FHWA in a Feb 2009 letter, more needed to be done.   

A Jan 12, 2012 presentation (3 years later) to the Sound Transit board described how they had selected a “Cesura” design for further development and testing.  A July 2013 presentation to the board detailed their plans to test this design at the Transportation Technology Center in Pueblo, Colorado during August and September.   

One would have thought there would have been some sort of status report at least to the Sound Transit Board.   Yet their agendas for October make no mention of the subject.  Apparently the tests are now scheduled for completion later this year.   It remains to be seen whether the lack of reports and extended testing are the result of problems.

Its not clear whether ST will proceed if the test results show the bridge can’t support four car trains.   Recent East Link depictions show only 3 cars in each train.  There is also the question as to how they will integrate 3 or 4-car East Link train operation with the 2-car Central Link trains. 

In reality the test results are largely irrelevant to a successful transit system.  Even 4 car trains will never have the capacity and accessibility needed for cross-lake mass transit needs.  The only way to do so is for two-way BRT on the center roadway.  This post is simply to illustrate the fact ST is spending hundreds of millions to finish designs of the Bellevue segments without confirming they can install light rail across the lake.   It sort of gives a whole new meaning to the phrase “Putting the cart ahead of the horse”.