The directors of NJ Transit have approved a contract worth more than US$1.5bn (£1.1bn) for the construction of the new Portal North Bridge.

The Portal North Bridge is a key element of the broader Gateway Program, which will eventually double rail capacity between Newark and New York.

The bridge project is designed to eliminate issues caused by the operation and maintenance of the existing 110-year-old swing bridge, which has been source of major disruptions for NJ Transit and Amtrak customers travelling on rail services along the Northeast Corridor.

The new structure will be a two-track, high-level, fixed-span bridge. It will run more than 15m above the Hackensack River and will allow marine traffic to pass underneath without interrupting rail traffic.

The US$1,559,993,000 construction contract for the project spans 3.9km of the Northeast Corridor and includes construction of retaining walls, deep foundations, concrete piers, structural steel bridge spans, rail systems, demolition of the existing bridge and related incidental works.

Once construction begins, the contract is anticipated to take approximately five and a half years.