A project which has introduced flexible speed limits in a bid to improve traffic flow on a notoriously congested part of the M6 has been crowned the region's top civil engineering scheme.

The 'Birmingham Box Phase 3 Smart Motorways' project built overhead gantries above the  motorway between Junctions 5 and 8 which tell drivers when they can use the hard shoulder and their maximum speed at busy times.

Last night, it was named overall winner at the annual awards run by the West Midlands branch of the Institution of Civil Engineers.

The 10-mile Birmingham Box project, which was carried out by Mouchel and Carillion on behalf of the Highways Agency, installed 21 new gantries and refurbished three existing ones, resurfaced more than 1 million sq ft of carriageway, laid almost 80 miles of cabling and constructed six emergency refuge areas.

The project, which encompassed significant sections of the motorway built on viaducts, follows on from the launch of the Midlands' first Smart Motorways scheme along the M42 in 2006.

In addition to being named overall project of the year, it was crowned top construction project.

Judges said: " The team successfully overcame the incredible challenge of designing and installing the latest Smart Motorways technology on this elevated and narrow corridor.

"This project has (won) the top accolade due to the complexity and degree of difficulty involved in fitting the construction in with existing viaducts, overcoming major safety challenges, maintaining the traffic flow of over 180,000 vehicles per day and the high level of innovation it demonstrated."

The awards celebrated design, innovation and engineering on projects which have been completed during 2013 and judges considered a total of 18 submissions across a broad range of categories, full details of which can be found here:

Last night's ceremony at the ICC welcomed music mogel Pete Waterman as guest speaker. The other winners were:

Innovation: A38 (M) Tame Valley Viaduct

Client: Birmingham City Council Partner: Atkins

The judging panel was impressed by the innovative use of the latest computing technology to monitor the structure and learn how it behaved whilst safely remaining open to the public.

Partnership: A45 Transport improvement corridor

Client: Birmingham City Council, Birmingham Airport Partners: Turner and Townsend, Solihull Metropolitan Borough Council

The £30m diversion of the existing A45 transport corridor included one mile of new dual carriageway, a new cycleway, bridleway and associated earthworks. In addition, the diversion of a major fuel main serving Birmingham Airport, diversion of the main sewer serving the whole of Solihull and the provision for public transport may facilitate Midland Metro services running to the Airport in the future.

Communication: Brumtunnels: Birmingham Tunnels Refurbishment Phase One 2013

Client: Amey Partners: Birmingham City Council, Syndicate Communications

Minimising disruption during the closure of the A38 St Chad's and Queensway tunnels during summer 2013 for essential maintenance was a major challenge. Judges were impressed by the use of modern and traditional methods which proved very effective in persuading people to use other modes of transport.

Sustainability: Connect2 cycleway and bridge

Client: Herefordshire Council, Partner: Amey

Opened in December 2013, this cycle route created safer access from Hereford to the south and Rotherwas Industrial Estate enterprise zone which aided regeneration, significantly reduced journey times for cyclists and included a 95m cable-stayed bridge with low maintenance costs.

Chairman's Special Award and Highly Commended for Partnership: Strongford P-Removal and sludge buffer

Client: Severn Trent Water Partners: Mott MacDonald Bentley, Offa-Fix Formwork, Carlow Precast

The project's main aims were to meet a new effluent phosphorous consent and to increase the efficiency of the onsite digesters and judges said it should be recognised as an example of a great project for the water industry.

Team Achievement: Community Centre canopy extension

Client: The Salt Peter Trust and Koutulai Grace Farmers Group Partner: Engineers for Overseas Development West Midlands

Designed to improve the lives of a co-operative of widows in Uganda, the Koutulai Development has been built over the last four years by a team led by Sarah Blick from Atkins.

The extension of the Midland Metro line in Birmingham city centre and a sustainability week run by Mott MacDonald were highly commended in the Innovation and Education categories respectively.

Rising stars from the sector were also recognised at the ceremony. A team from Amey comprising Jack McCrone, Pip Jefferis and Tom Royds won the Graduate and Student Communications competition while Jose Nogueron from Aecom took home the Graduate and Student Paper prize for his work 'Shaping the Cycle Infrastructure of the Future'.