Sound Transit’s East Link is the first attempt at installing light rail on a floating bridge. The concern has been the durability of the expansion joints that connect the floating portion of the bridge with the fixed structure at either end. The origina1 I-90 joints have already needed to be replaced, presumably because of degradation from existing vehicular traffic.
Each loaded light rail car weights 74 tons, so a 4-car train represents a substantial increase in loads for the expansion joints. The Washington State Department of Transportation (WSDOT) conducted a test in September 2005 to simulate light rail operation on the bridge. The test involved eight flatbed trucks that were loaded to approximate the weight of light rail vehicles (148,000 pounds each, with two four-truck combinations each simulating a four-car light rail train). 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”.
However, the U.S. Department of Transportation Federal Highway Administration, in a February 25, 2009 letter, HRW-WA/WA624 responding to Sound Transits 2008 Draft Environmental Impact Statement (DEIS) for the East Link Project had a different opinion. Paragraph 5 of the letter concluded “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”.
Chapter 7 of the 2011 Environmental Impact State did include a “Response to Common Comments” section that provided the following information concerning installing light rail on a floating bridge structure.
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. See Section 2.3.2 of Chapter 2 for further information.
Section 2.3.2 of Chapter 2 doesn’t have any information on the bridge structural concerns and the conclusion “all issues identified as potentially affecting feasibility can be addressed” is surely open to interpretation. For instance, they could address concerns by reducing the number of cars in each train from 4 to 2, halving the already meager capacity. It’s also not clear whether the FHWA agreed with the IRT conclusion.
What is clear is that Sound Transit hasn’t conducted any more structural tests on the bridge. The wording concerning future studies of the expansion joint design is also exactly the same in the two EIS’s suggesting little has been done in the more than 3 years since FHWA raised concerns.
It’s another example of how Sound Transit’s has spent hundreds of millions promoting and planning light rail but very little on whether the damn thing is going to work. What’s outrageous is they are counting on the WSDOT, the legislators, and the media to allow them to continue doing so for the next four years after which it will be too late to stop them.
That's why I run.