Remarkable progress is being made on a £330 million improvement scheme on the A1 in Yorkshire.
The objectives of the improvement are to reduce current high levels of accidents and congestion and enhance journey time reliability by upgrading the existing the existing A1 to dual 3-lane motorway standard. The project is being carried out by Carillion – Morgan Sindall JV on behalf of the Highways Agency. The contractors are working with design partner AECOM and works began in March 2009.
A great deal of carriageway construction is involved in the scheme – 2.5Mt of earthworks, 1Mt of imported starter and capping layers and 980,000t of sub-base and asphalt. JV project director Chris Hayton said: “Logistics are a challenge on this project given the sheer volume of deliveries and the need to manage them safely.
“We have 700 people working out here. Safety is our number one priority. Nobody is allowed to cross the A1 and we have 250,000 wagon loads on and off site to manage. When divided by the number of working days we have, it works out that we have to handle on average 60 vehicles an hour. It’s a massive issue because we cannot have vehicles queuing to discharge and backing up at access points”.
In Section 1 (Dishforth to Baldersby) the Baldersby East Roundabout is now fully open to the public and is in operation with northbound traffic directed along the new Local Access Road (LAR) to join the A1 north of Sinderby. A1 mainline traffic is now running in contraflow on the new northbound carriageway with drainage, earthwork and landscaping works continuing on the southbound carriageway.
In Section 2 (Baldersby to Sindersby) traffic is running in contraflow on the new southbound carriageway. The old Butcher House bridge and Sinderby Rail bridge have been demolished. Earthworks and drainage works on the A1 northbound continue.
In Section 3 (Sinderby to Gatenby) construction of the Street Lane embankment adjacent to the northbound Local Access Road is complete. Traffic is diverted over the new embankment for the Street Lane tie-in to the Local Access and the closure of Shipley Lane is required as part of these works. Traffic is now running in contraflow on the newly constructed southbound carriageway between Gatenby and Street Lane (Pickhill Junction), whilst earthworks at Oaktree underpass are underway on the west side of the A1.
In Section 4 (Gatenby to Leeming) the new Leases link road is now open to the public. The existing slip roads on the southbound carriageway from the A1 to Leeming services have now been closed with access to the services gained via the new link road. The site itself is now operating as an island site with the southbound traffic running on the new southbound carriageway and the northbound traffic running on the existing A1.
To illustrate the level of care put into the logistics of the project, Chris said: “The project makes the best possible use of ‘site-won’ materials to minimise the import of first generation stone. Stone brought to site is sourced locally to minimise our carbon footprint but balanced out amongst local quarries to minimise the impact of wagon journeys on the local population along the delivery routes”.
He added: “We have banned works traffic from using many of the local roads and we are conscious of the volumes of imported stone, both dry and coated. We have worked with our suppliers to minimise our impact on the local population. Great effort has been made to inform the public in advance of our proposals in our effort to minimise disruption and accelerate completion of the project.
“We have restricted working hours where possible to 07:00 – 19:00 Monday to Friday and have generally avoided working weekends. There have been some works for which night shift working has been necessary and, whenever such working might impact upon neighbours, they have been advised of the proposals in advance and offered alternative accommodation if appropriate.”
Chris explained that his team had been using a ‘lean construction’ approach to streamline the work. He said: “We cannot afford for deliveries to be interrupted, so in addition to supply contingencies, plant maintenance is carried out at night. A time and motion study showed we could aim to lay 2000t in a day, provided the asphalt gang was kept working from 7AM to 5PM.” All pavement cuts are pre cut in the evening and there is no waiting around or checking of ‘dips’ in the morning. Levels are controlled from concrete safety barrier foundation slabs and surface water channel.
Working with care
The road passes through a Scheduled Ancient Monuments (SAM), site where considerable archaeological findings were during investigation and recording by a team of 35 archaeologists.
There has been a considerable ecological input into the scheme to deal with various protected species – badgers, otters, bats, great crested newts and nesting birds – and the site team has had to deal with a number of noxious or invasive plants such as giant hogweed, Japanese knotweed, Himalayan balsam and ragwort.
Chris added: “The drainage from the existing A1 issued directly to local watercourses. With the new scheme, all the water from the new road flows to balancing ponds, which attenuate the flow to watercourses and carry out initial settlement of solids as well as some treatment of pollutants through the action of reed beds.”