Neal Doyle captured a new commuter-rail train chugging along the Grand Junction rail line in Cambridge towards the Charles today.

The T and Amtrak occasionally use the line, which crosses the Charles under the BU Bridge, to transfer trains from the north side of Boston to the south - it's the only north/south link inside 495. State officials hope to one day use the line to connect the Worcester Line to North Station, although Cambridge city officials remain opposed.