The reason for closing the bridge is this bypass. The 300-foot-long section of double decker bridge is angled in a way that can route traffic away from where the new bridge is going. The bypass is expected to be in place until 2013.
After it's installed, the old section of the bridge will be dismantled, and its steel recycled. But before that can happen, both football field-sized slabs of concrete and steel must be slid into place by something called a skid jack.
This one in particular (which looks like two I-beams sitting below the section of the bridge), has been put together by Holland-based Mammoet. Its instantly-identifiable red coloring is almost lost in a sea of support systems, including steel girders that reach hundreds of feet into the air.
The skid jack system uses eight jacks (two on each corner), all of which help to lift up the load, allowing it to be slid with relative ease. Once cut, the slab of the old bridge slides on double-sided Teflon pads that are lubricated in dish washing soap. It moves a little more than a foot at a time, but is much safer than attempting to pull up the entire, aging slab.
Want to know more about the bridge project and how it's going? You can see video flyovers of what it will look like, and see time lapse video of this weekend's move at its official site.