Winner - Highways Magazine Excellence Awards 2010 traffic flow improvement scheme of the year
M4 Junction 24 Coldra roundabout improvements scheme
The South Wales Trunk Road Agency along with the Welsh Assemb ly Government, Alun Griffiths Contractor Limited and Capita Symonds, have won the Highways Magazine Excellence Award 2010 for the Traffic Flow Improvement Scheme of the Year for the M4 Junction 24 Coldra Roundabout Improvements Scheme.
The award ceremony took place on the 20th October 2010 at the Milennium Hotel in London Mayfair. Judges deemed that the M4 Junction 24 Coldra Improvements scheme has demonstrated significant traffic flow improvements in the area providing more reliable journey times and improved pedestrian and cyclist provision. Entries were judged against a range of criteria including:
- Outline of problem addressed and approach to indentifying the development of the solution
- Quality outcomes of the scheme
- Impact of the scheme on road users and the community
- Any additional sustainability considerations
The Coldra roundabout at Junction 24 of the M4 is the main gateway into newport from London and the Midlands. The busy junction made local access difficult, with limited provision for pedestrians and cyclists. Traffic flows had exceeded maximum caoacity leading to long queues and delays in the area.
The Welsh Assembly Goverment's Agent the South Wales Trunk Road Agency, appointed Capita Symonds as designer for the scheme. Alun Griffiths (Contractors) Ltd undertook the construction of the scheme.
The aim of the project was to improve the capacity of the junction and the local environment for those that live and work in the area.
A key element of the scheme included the construction of a 'Hamburger Arrangement' providing a direct link through the central island from the A449 southbound to the M4 westbound - this movement having the highest traffic flow. The new layout dramatically reduced the traffic on the gyratory. In addition, an advanced traffic control system was provided using Microprocessor Optimised Vehicle Actuation (MOVA) and incorporating pedestrian and cycle facilities. Additional lanes were provided on the gyratory and dedicated lanes from the M4 motorway further reduced the amount of traffic using the roundabout. A new pedestrian cycle way was constructed through the central island linking existing pedestrian and cycle ways and enhancing the SUSTRANS cycle network.
As the Coldra roundabout is home to a number of protected animal and plant species, surveying and mitigation measures followed strict guidelines. A new sign gantry was also utilised to link extensive dormouse habitats in the area.
Other environmental enhancements included soft landscaping, use of felled trees to create reptile habitats and use of excavated material in landscaping features. Surface water runoff is held in an underground storage facility prior to controlled discharge into the existing drainage.
The £5 million scheme was completed in July 2009 but dormouse monitoring will continue for five years anda two year landscaping plan will help establish the new landscaping works.
The scheme was also the runner-up in the CIH/TRL Awards receiving a 'Highly Commended' in the Environmental Improvement category. Thsi scheme has improved traffic flows, reduced congestion and enhanced the local enviroment. It has also provided a benefit to the Welsh economy as a whole.
