Along with the harbor tunnels and the Turnpike from Route 128 to East Boston, it is part of the Metropolitan Highway System.

Business leaders were more concerned about access to Logan Airport, and pushed instead for a third harbor tunnel.

Construction on the harbor tunnel, the first phase of the project, is now expected to start this fall.

Q. Various proposals for a harbor tunnel and expanded port have been around for more than 50 years.

A highway, railroad, suspension bridges and a harbor tunnel were part of the $20 billion package, along with a new town, Tung Chung, population 20,000.

Get off there, follow the white arrows under the harbor tunnel, through the quarantine exclusion zone, and past the water.

Several times a week, traffic in East Boston waiting to enter the Boston-bound harbor tunnel backs up all the way to the airport.

Citic is also a significant investor in a new harbor tunnel in Hong Kong.

Once an island, East Boston is now connected to the city by two harbor tunnels.

A harbor tunnel would shift the system out of balance.