The Coronado Bridge has a giant zipper running down its middle – really!
Coronado Bridge Zipper
It is not a traditional zipper. It is a moveable barrier made up of concrete segments 2 feet wide by 3 feet long each linked to adjoining segments with large steel pins.
For those not familiar with it, the Coronado Bridge is a five lane bridge with four 12-foot lanes on either side and a 14-foot lane in the middle. It is in this middle lane where all the magic happens.
The middle lane is a reversible lane through the engineering feat of the “zipper”. On weekday mornings, when traffic is heavy coming into Coronado, there are three lanes open for west bound traffic. After the morning rush of Naval Base traffic, the transfer machines move the concrete zipper barriers reversing the direction of the middle lane so that there are three lanes open for the leaving east bound traffic that afternoon. Once the majority of that traffic has left Coronado, the transfer machines reverse the middle lane again in preparation for the morning traffic.
Stacy Marie was lucky enough to join the Caltrans team June3, 2009 and wrote about it in her blog along with some great photos. It is really an amazing thing to see, and you can see it every weekday (except holidays). And if you happen to see my buddy Jerry, give him a smile and a wave ~ he always makes me smile 
Tags: Coronado Bridge, Coronado Bridge Zipper, Coronado traffic