Local transport minister Norman Baker today confirmed funding for the project, which will tackle a bad traffic bottleneck.
The original bridge was built to carry a dual carriageway road but is now too weak to do so and traffic has been restricted to a single lane in each direction for a number of years.
The new bridge will allow the dual carriageway to be reinstated as well as removing any weight limit, bringing the bridge up to current national standards.
Construction work gets underway next month on the new bridge, which is scheduled to open in October 2013.
The Northern Road Bridge project was one of the schemes given funding approval last year as part of the spending review process.
Baker said: “The £11m we are putting into this scheme shows that the Coalition Government is serious about investing in the infrastructure the country needs to drive economic growth.”