520 tolling on track to fund new floating bridge



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Posted on January 6, 2012 at 7:51 AM

Updated Friday, Jan 6 at 1:52 PM

SEATTLE -- Washington state needs tolling money to help pay off the new 520 floating bridge. So will SR 520 get enough traffic?

On Friday, Washington Department of Transportation officials said funding is still on track.

According to traffic data from the first week of tolling, WSDOT says 520 traffic is down 75 percent of pre-tolling levels during the morning and evening commutes, and overall daily volume is down 23 percent.

To pay off the bonds for the new bridge, WSDOT said they made a conservative estimate and accounted for a 48 percent drop in traffic on the tolled 520. So, still expect construction of a new floating bridge to begin near Medina in April.

WSDOT webcams show giant concrete pontoons - floating pieces where the highway will sit on - are being built. The largest pieces are a little larger than a football field and 30 feet tall.

Construction is at full speed ahead. WSDOT crews are building six pontoons at a time of various sizes in Aberdeen and Tacoma, and bridge footings are being constructed in Kenmore.  All the pieces will then be floated to Lake Washington, where they'll be pieced together like Legos.

Unlike the current span, the new floating bridge will have a new pedestrian path. It will be longer and stronger and have a  75-year life span instead of 50.

"When we get to 45-mile-an-hour sustained winds for 15 minutes or more, we do have to close the bridge, open the draw span," said Mike Cotten, WSDOT floating bridge project director. "The new bridge will not have a draw span and is being designed to a higher standard to sustain over 90-mile-an-hour winds on the lake."

So what will happen to the old bridge when the one is finished in two years?

"The design builder is still looking at options to what they do with it, whether it becomes recycles material in other projects or it may be possible for exsisting peices of the bridge to be sold off and used in other applications," said Cotten.

WSDOT crews will start piecing the pontoons on the lake in Medina first.  When they float the largest pieces up from Aberdeen, the pontoons will barely squeeze through the Ballard Locks. WSDOT says there will only be two feet to spare on each side.