Investment in infrastructure has always played an important role in boosting local economies, improving mobility and trade connections. This role becomes even more important in times of economic instability, despite the fact budgets are tighter and funding can be hard to find.

Nevertheless, huge and complex road and bridge projects are getting the green light worldwide, from Europe, the Middle East and the US to the ever-expanding BRIC nations. Here we profile ten of the largest and most technically challenging.

Doha Expressway, Qatar

The Doha Expressway is a four-lane highway project that will connect the south of Doha with the north, east end west, replacing the current two-lane dual carriageway. Undertaken by the Public Works Authority of Qatar (Ashghal), it aims to provide a modern road network throughout the city in order to improve the flow of traffic and reduce congestion, journey times and environmental impacts.

Work kicked off in 2007 and is carried out in 13 phases. Several of them have already been completed. The total scope of work includes 30 major expressway projects, 550km of highways and more than 80 interchanges. Estimated to cost about QR15bn (£2.78bn), the project is scheduled for completion in 2015.

Bayonne Bridge, New York, US

Connecting the cities of Bayonne, New Jersey, and the Port Richmond area of Staten Island, New York, the 1,675ft-long Bayonne Bridge is one of the world’s longest steel arch bridges. First opened to traffic in November 1931, the channel span of the 151ft high bridge has always been too low for large container ships to pass under.

After a feasibility study in 2009, the Port Authority decided to expand the height of the roadbed to 215ft and allocated $1bn to fund the project. The works include a new roadway within the current arch structure and the removal of the existing roadway.

It also involves widening each of the four lanes from 10ft to 12ft and uplifting the existing approaches, ramps and main span roadway. Construction is set to start within the next few months and expected to be completed in 2014.

Rohtang Tunnel, Lahaul-Spiti Valley, India

“The horseshoe-shaped tunnel was proposed in 1983 but work only began in July 2010.”

The 8.8km Rohtang Tunnel is currently being built under the Rohtang Pass in India’s Lahaul-Spiti Valley. Upon completion in 2015, it will reduce the distance between Manali and Keylong by more than 60km and reduce travel time by more than four hours.

The horseshoe-shaped tunnel was proposed in 1983 but work only began in July 2010. It will be laid at a general altitude of 3,000-3,100m and will be the world’s longest tunnel at such high altitudes. The road is set to be 10m-wide and will have a footpath of 1m on either side. The project also includes the construction of access roads on either side to connect the Manali-Leh highway, which was completed in 2005.

The tunnel will be constructed using drill and blast New Austria Tunnelling Method (NATM) techniques. Rough weather and avalanches however have hampered progress and makes work for main construction contractor Afcons-Strabag dangerous.

Deh Cho Bridge, Canada

The $182m Deh Cho Bridge is a cable-stayed bridge under construction since 2008 in Fort Province, Canada. Once completed, it will span 1,045km across the Machenzie River, connecting the Northwest Territories community to Alberta.

The bridge will replace a ferry service and an ice crossing, which only exists for three to four months in winter. The cable span will have a length of 190m, and will appear symmetrical when viewed from the centre.

Being built by the Deh Cho Bridge Corporation together with the Government of the Northwest Territories (GNWT) Department of Transportation, the bridge was originally scheduled to open in November 2010. However, due to delayed delivery of steel, the opening is now planned for autumn 2012. Moreover, during final approval of the plans by the GNWT, design inadequacies of the superstructure by JR Spronken and Associates were discovered.

Fehmarn Belt Tunnel, Germany / Denmark

The Fehmarn Belt Fixed Link is an immersed tunnel proposed to connect the German island Fehmarn with the Danish island Lolland. Originally envisaged as a bridge, project leader Femern announced in December 2010 that a tunnel was preferable due to fewer construction risks. The Danish Government approved the project in January 2011 but a final decision will not be made until 2012.

The proposed tunnel would be 17.6km long, 40m deep and carry a two-lane highway as well as a double-track railway. It would be the longest immersed tunnel ever constructed, the longest ever combined road and rail tunnel, the world’s longest underwater tunnel for road and the deepest immersed tunnel with both road and rail traffic. Planned completion of the tunnel is 2020.

The crossing has been discussed for more than 30 years. Critics have however expressed the environmental impacts the project could have as well as social impacts, such as job losses, in connection with the present busy ferry traffic.

M74 completion project, Scotland

Scotland’s huge £445m project to complete the M74 motorway, filling in the missing link in Glasgow’s surrounding ring road and join up the M74 with the M8 to the west of the city, had been gestating for years before construction started in 2008. Once this massive motorway project began construction, however, contractor Interlink M74 Joint Venture completed work on time and on budget, with the new motorway opening to traffic in June 2011.

The joint venture contractor certainly had a colossal amount of work to complete in just over three years. More than one million tons of earthworks were excavated and replaced with 24,000 tons of low noise surfacing, along with 500 concrete beams, more than 30 gantries equipped for electronic signage and 70,000m³ of structural concrete.

While some groups have criticised the scheme for increasing air and noise pollution for nearby residents, Glasgow City Council head Gordon Matheson told the BBC its opening was a ‘a momentous day for Glasgow and for Scotland’.

New Mississippi River Bridge, US

For the first bridge built over the Mississippi River connecting St Louis and Illinois in 40 years, the states of Illinois and Missouri had to downscale their initial ambitions due to financial constraints.

“For the New Mississippi River Bridge, the states of Illinois and Missouri downscaled their ambitions.”

The redesigned project might have chopped the bridge’s cost down from around $2bn to $667m, but it will still be third-largest cable-stayed bridge in the US on completion in 2014.

The bridge, along with associated road works, will give drivers a much more direct route across the river on Interstate 70 with the intention of reducing congestion and improving connectivity between the two states.

The bridge will have two lanes in each direction, but has enough width to be converted into six lanes if traffic warrants it.

Amravati-Maharashtra / Gujarat Border Highway, India

Like other BRIC nations, India is investing heavily in infrastructure projects to increase mobility and help stimulate economic growth.

One of the largest road projects the country is embarking on is a $1bn, 485km highway linking Amravati in the state of Maharashtra to the Maharashtra-Gujarat border.

The four-lane road is being built as an alternative to the under-construction East-West Corridor and was announced in September 2011.

Although this project is still in its early stages with no tenders announced (although The Times of India has noted high interest from domestic and international infrastructure companies), when completed it will cut the distance between Mumbai and Kolkata by 300km and provide a direct link between Mumbai and the strategic port town Hazira in Gujarat.

Sava River Bridge, Serbia

“The 1,200ft single pylon cable-stayed bridge will be the largest of its kind in Europe upon completion.”

The Sava River Bridge is one of the largest infrastructure projects in Serbia, a six-lane bridge spanning the River Sava and offering an extra route into the capital Belgrade.

It is also an attempt to reclaim Serbia’s engineering prestige and improve infrastructure in support of the country’s plan to join the European Union. The bridge, a 1,200ft single pylon cable-stayed bridge that will be the largest of its kind in Europe upon completion, looks set to earn the prestige the country is seeking.

Its ambitious, iconic single pylon design will also serve to minimise disruption to shipping on the river, an important pillar of the regional economy. The entire project is estimated to cost around £320m, with extra funding coming from the European Investment Bank and the European Bank for Reconstruction and Development.

First traffic is scheduled to cross the bridge on 15 December 2011, with the entire project due for completion in 2013.

Qatar-Bahrain Causeway, Persian Gulf

The ambitious joint plan to build a 40km causeway connecting the northern tip of Qatar with Bahrain’s eastern coast has had a troubled history. Construction has been pushed back from early 2009 and has still not officially begun, but reports from earlier this year suggest this massive project is due to get underway before the end of 2011, with a project cost of $5bn and a completion date of 2015.

The main reason for the delay has been a redesign to include not only a two-lane motorway on the bridge but also a rail line that would integrate with Bahrain’s light rail network.

This mega-project is undoubtedly important for the two states’ economies but it is also intended to symbolise closer ties between Qatar and its smaller neighbour, a sentiment encapsulated by the causeway’s unofficial name: the Qatar-Bahrain Friendship Bridge.


By Elisabeth Fischer and Chris Lo