Glimpses of a new 20km bypass taking shape through green fields to the south of Huntingdon can be seen by motorists and hauliers travelling west away from Cambridge on the often congested A14.

 

This off line improvement forms a major component of a £1.5Bn, 34km upgrade to the main highway between the market town and the city. It also serves as an enticing reminder that relief promised from heavy traffic and disruption on the major route is not too far away.

 

On line widening beside the existing A14 near Cambridge, construction of a northern bypass around the city and parallel improvements alongside the A1 near Alconbury to the west also form significant elements of the project.

 

But it is off line of the busy road on the southern bypass of Huntingdon where most of the construction activity is currently focused. Here, piled foundations and concrete columns are being installed for a 750m long viaduct to lift the new dual three lane carriageway out of a flood plain and across the River Great Ouse.

 

Rotary bored piles are being created to a depth of 36m, passing through river terrace gravels, to support rows of four columns that will form 16 bridge piers and two abutments. Weathering steel beams will start to be placed in October, followed by the installation of 534 concrete panels for the deck and 252 concrete parapet cope units, to be precast in a facility on site.

 

Access over the river for construction traffic is currently provided by a temporary steel bridge, which replaced a floating pontoon used in the very early stages of site activity.

 

Work has also begun adjacent to the viaduct to build abutments for a bridge that will carry the road over the four track East Coast Mainline railway. In all, the A14 upgrade will see 30 bridges constructed and the movement of over ten million cubic metres of material; the majority sourced from local borrow pits providing aggregate and clay.

 

Across the whole project there are 120 dump trucks, 60 excavators, 60 rollers and 40 bulldozers working away. The site will see a peak in personnel later this summer, up from 1200 in recent months to nearly 2300.

 

The highway improvement is split into six sections (four of which are under way) and works are being carried out by the ‘A14 Integrated Delivery Team’ which brings together joint venture contracting partners of Atkins / CH2M, Costain / Skanska and Balfour Beatty / Carillion.

 

Several major new junctions will be built beside the existing A14 including one at Bar Hill, to better serve a community with limited access to the trunk route. Existing interchanges to be remodelled include Girton where the M11 and A428 meet the A14.

 

Haul roads have been built to keep construction traffic away from the public highway and local access roads will be created beside the on-line section of A14 being upgraded, to give local drivers the option of reaching Cambridge using a quieter route.

 

“This job features great structures and bulk earthworks on a scale that have not been seen since the M6 Toll was built over 20 years ago,” remarks construction director Jim McNicholas MCIHT. “The only thing we don’t have is a tunnel!”

 

He adds that new highway through the off line section is set to take the form of a continuously reinforced concrete pavement. Around 134,000m3 of concrete pavement is to be formed using a slipform paver; making use of aggregate won from the local borrow pits. The concrete base will be overlaid with a 35mm asphalt surface course.

 

Highways England project manager Chris Griffin says the scheme will not only significantly reduce journey times but make a positive impact on local communities when it completes in 2020. “The A14 is used by 85,000 vehicles a day and the vast majority of those will be transferred to the new road.

 

“Typically the time taken to drive between Huntingdon and Cambridge will reduce by up to 20 minutes when the improvement is complete. At the moment any incident can lead to gridlock.”

 

He adds that heavy goods vehicles currently account for a quarter of the traffic on this stretch of the A14. It is thought that the number of lorries using some sections of the route could grow by as much as 40% by 2035.

 

The final piece of work to be completed on the improvement will be the demolition of a viaduct and removal of embankments carrying the A14 through Huntingdon.

 

Chris Griffin adds: “For me the A14 is a ‘seed’ project that marks the start of several other important upgrades locally including the A428 and A47 improvements that will follow close behind, plus work to create a new route from Oxford to Cambridge.

 

“We have recruited 75 apprentices on this project and hopefully they will stay with us for the next 10 to 12 years to work on the next set of schemes.”