The US state of New Hampshire has approved a $50m contract to begin overhaul work of the Little Bay Bridges between Newington and Dover.

The US-based contractor Cianbro Corporation will work on the project to double the size of the narrow bridge from four lanes to eight, and upgrade another parallel bridge used by pedestrians and cyclists.

The contract is the first phase in the $238m project, which includes a new roadway on the Newington and Dover approaches, and changes to the access at the General Sullivan.

The Little Bay project that is scheduled to be completed by 2013 is intended to alleviate traffic congestion on the bridge, according to seacoastonline.com.