by Diverging Route
Ballast has been laid about half-way across from the Cambridge end, on the new permanent Boston-bound track. Ballast has been laid on the shoo-fly from the Cambridge end to about the first tower. Today, they're installing Jersey barriers to protect traffic from the new shoo-fly on the upstream side of the bridge -- progress now is only about 100 yards from the start of the track (which as you can see from the picture is not connected).
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