CEEQUAL Excellent (82.0%) – Whole Team Award
Version 5, May 2016 | Johnston, Haverfordwest, Wales
Sustainability Strategy: Excellent (93.3%)
The Bulford Road Improvement project was conceived and designed to provide significant improvements to a single lane road between the Pembrokeshire villages of Tiers Cross and Johnston. Although the road is narrow in nature with substandard vertical and horizontal alignment, and has high hedgebanks along the greater part of its length, it is subject to a relatively high proportion of use by heavy goods vehicles, as it serves the major strategic energy sites of Murco Oil Refinery, South Hook LNG site and other development sites located to the west of Milford Haven. The alternative access to these sites is generally via Milford Haven Town Centre and a restricted height bridge.
As a single lane road, Bulford Road’s condition made it a particularly difficult route for all road users, including pedestrians and cyclists and those who live in the properties fronting onto the road.
Improvements to Bulford Road were identified as being of strategic importance in the context of carrying trunk road traffic to nationally important energy sites and other developments. It also contributes to strategic priorities set out in various national, regional and local level policies.
The project was designed to provide considerable improvements to the existing road link, and consequently to the surrounding area, by alleviating existing constraints within the route. The scheme provides improvements to a 2.7km section of road including:
- A new 7.3m wide carriageway with 3.5m verges.
- A shared cycleway and footpath to the northern side of the carriageway. This runs from the junction with the A4076 in the east, to a point where it diverts onto the bypassed section of Bulford Road to the east of Tiers Cross. The new shared use route links with the National Cycle Network (Route 4 Celtic Trail).
- New roundabout junctions constructed at each end of the realigned road.
Challenges and achievements
Sustainability from the outset
Pembrokeshire County Council’s Environmental Sustainability Policy was a key driver in the development of the concept design of the project. The objectives of the project were to:
- Improve traffic efficiency, with the aim of reducing greenhouse gas emissions
- Enable bus access along the road and thereby promote sustainable transport
- Utilise local sustainable materials
- Promote biodiversity
- Improve the quality of the local built environment, and
- Minimise the risk of pollution.
Improvements to Bulford Road project were identified as a priority to the Regional Transport Plan for south-west Wales, and as a key mechanism to provide significant contributions to the local economy, community, transport and safety.
CEEQUAL was selected as the tool to both record sustainable aspects of the project and to identify areas for improvement.
Development of the design
Optioneering for the project reviewed various strategies to provide the improvements needed to address the issues with the existing road. The chosen option involved the creation of a new offline road whilst retaining the existing road for local access. This option was supported through considerable stakeholder engagement and consultation, as well as reviews of ecological, heritage, noise, and traffic investigations.
Whilst the project has required the construction of a new road, measures have been taken where possible to provide ecological enhancements and improve the overall biodiversity of the project area. For example:
- The 1.7 km of species rich hedgerow lost as a result of the project was replaced with 3.6 km.
- New woodland was created.
- A sustainable drainage system was implemented with the creation of new ponds.
- Three mammal underpasses were created for badgers and otters. (And indications post-construction are that these underpasses are being used.)
- The stream culvert under the road was oversized to allow access through it for foraging bats.
- Measures were taken during construction to maintain foraging corridors for bats through the creation of temporary hedgebanks using cut vegetation.
Sustainability through the construction stage
A lifecycle assessment was undertaken for the project with the following objectives:
- Select materials to achieve a high quality scheme – constructing a section of highway that will be durable, low maintenance, and incorporates recycled materials.
- Provide a new section of highway which sits down into the landscape and is not visually obtrusive. (The vertical alignment of the project was assessed as part of this to seek an earthworks balance for the project. Modifications included amending the culvert design from a concrete box culvert to a segmental steel arch, thereby allowing for a slightly lower level of construction in this section.)
- Provide a landscape design in keeping with the surrounding vegetation and landscape, as well as being biodiverse and of native provenance.
- Minimise the impact of the project on surrounding wildlife and habitats.
- Use construction methodologies to minimise environmental impacts and impacts on the surrounding community:
- Local suppliers were identified as possible sources for materials, and
- Material specifications in the design were reviewed to enable the use of recycled materials.
- Develop a solution which fulfils the above requirements within the scheme budget.
- Modify the design so as minimise the requirement for additional works:
- A key part of this was changing the alignment at the western end of the project to avoid the need to divert a 250mm water main and telephone infrastructure. This change also enabled a greater area of green landscaping to be created within the project’s footprint.
- Another key aspect was to amend the vertical alignment to reduce the amount of imported fill material that would be needed, and thus reduce movements of HGVs on the wider network during the construction stage.
The site compound utilised an existing brownfield site, located in an existing farm yard, accessed from Bulford Road. This was shared with a haulage company.
Case study by Atkins Ltd, with contributions from Alun Griffiths (Contractors) Ltd and Ramboll.