After the completion of the Ml, M2, M5 and Westlink the next major scheme was the construction of the Belfast Cross Harbour Bridges. As this was a very large scheme various proposals were considered and there were several postponements. A further review of the Belfast Transportation Strategy in the 1980s concluded that the construction of road and rail links across the River Lagan were essential parts of the transportation infrastructure not only for the city, but for the Province as a whole.
The decision to proceed with the scheme was taken in May 1987 by the Minister Mr (later Sir) Richard Needham.
It was decided to proceed by way of an international design and construct competition which attracted eleven consortia from five countries. Six were selected in November 1988 to submit outline designs. The Royal Fine Art Commission advised on the aesthetic merit of the designs. Three consortia submitted tenders in March 1991 and the contract was awarded to the Graham Farrans Joint Venture. The design was done by Acer Consultants (formerly Freeman Fox and Partners) in association with W D R & R T Taggart for Graham-Farrans with Robert Benaim and Associates providing assistance with temporary works and deck erection procedures.
The Department of the Environment (NI) was the client for the roads part of the contract and also acted on behalf of Northern Ireland Railways for the rail portion. Ove Arup and Partners acted as engineer to the contract and as design checker. There were in all, about 40 contracts and work on the main contract started in August 1991.
The scheme connected the M2 and West Link near Dock Street with the East Belfast road system at Middlepath Street. The length of the road structure is about 790 metres and the adjoining rail structure is about 1490 metres long. There are three separate structures - road east bound, road west bound and rail. The bridge decks are of concrete box construction using glued precast match cast post tensioned segments weighing between 55 and 95 tonnes each.
The ending at Middlepath Street was temporary, as the direct connection to the Sydenham By-Pass could not be constructed until the railway maintenance facilities near Bridgend had been relocated on the Antrim side of River Lagan.
The rail bridge was opened to traffic on 28 November 1994. It connected the Larne line to the Central Station. On the previous Saturday, pedestrians were allowed to walk over the road bridges to see the work and there was a charity bed push. The road bridge was opened to traffic on 22 January 1995.
In February 1994, Sir Patrick Mayhew, Secretary of State for Northern Ireland, visited the site and named the road and rail crossings as the Lagan Bridge and Dargan Bridge respectively. The road is now known as M3.
On 9 March 1995 the road and rail links were formally opened by Her Majesty Queen Elizabeth II. She had opened the nearby Queen Elizabeth Bridge, which, after some controversy, was named after her, on 4 July 1966. It had come into use on 3 April 1966.
The second part of the M3 scheme brought the motorway to near Dee Street on the Sydenham By-Pass. This was also a design and construct project. It was carried out by Farrans (under John Gillvray) for whom the design was done by Tony Gee. It involved the demolition of the 1959 Ballymacarret viaduct over the railway and the construction of a new railway tunnel to carry the westbound off slips.
This portion was completed in May 1998 - some 60 years after Duncan started work on the construction of the Sydenham By-Pass.