East Lyme — Amtrak plans to shift all rail traffic tonight to the new Niantic River Bridge and remove the existing 105-year-old bridge from service.

“This is a major accomplishment in Amtrak’s effort to renew and improve northeast corridor infrastructure for the next century of service,” President and CEO Joe Boardman said in a statement.

The last train to run over the old bridge will be Northeast Regional Train #67 from Boston to Newport News, Va. at about 11:39 p.m. Friday. The first train to operate over the new bridge will be Northeast Regional Train #66 from Newport News to Boston at about 5:24 a.m. Saturday.

Amtrak built a two-track, electrified, railroad bascule bridge across the Niantic River between East Lyme and Waterford, 58 feet south of its current location. Initially all rail traffic will share one track over the new bascule lift bridge.

The second track is scheduled to be ready in November. Amtrak will continue to open and close the old bridge for maritime traffic until it is fully removed next spring.

The $140 million project began in April 2010 and remains on schedule to be completed in May 2013.