Key Facts
- Client: Highways Agency
- Balfour Beatty company involved: Balfour Beatty Civil Engineering
- In 2003, Balfour Beatty Civil Engineering was awarded the £148 million contract to widen the 10-mile stretch of the M25, between Junction 12 (the M3 Interchange) and Junction 15 (the M4 Interchange)
- The M25 orbital route around London is one of Europe’s busiest motorways, carrying more than 200,000 vehicles a day on this section
- The contract also included the construction of the Stage 2 Heathrow Terminal 5 Spur Road, a dedicated 1km-long free-flow connection to Terminal 5 via an altered Junction 14, for which the client was BAA
- The project began in early 2004 and was completed in only 100 weeks in December 2005
- The first section, between Junctions 12 and 14, was widened from four to five lanes and the second section, the remainder to the M4 Interchange, from four to six lanes
- All the widening works were completed within the existing highway boundary, with no additional land-take necessary, using a combination of steepened earthwork slopes and piled reinforced-concrete retaining walls
- Traffic was kept flowing by well-planned traffic management, comprehensive surveillance using 110 CCTV cameras and an on-site control room, high-quality vehicle recovery and a reception area for stranded motorists
- Surrey Police reported a 25% reduction in injury collisions on this section of motorway during the widening construction, compared to the year before
- Over 90% of aggregates and fills used in the project were from recycled sources, measures which resulted in a National Award for the project from Highways Magazine
- Other achievements included setting up the first dedicated off-site recycling facility for the supply of aggregates to a major motorway contract, and reducing waste disposal by recycling and maximising re-use on site
- A constant communication and media campaign kept local residents, businesses and the travelling public well-informed
- Balfour Beatty has a substantial amount of successful experience of working in the south-west quadrant of the M25 in terms of both original construction and subsequent widening
- It was responsible for the original construction of the southern end of the Junctions 12-15 segment and, subsequently, for its widening in the late 1980s
- Other previous work includes the M25 Junctions 8-10 contract, worth £93 million, and the M25 Junctions 10-13 contract, worth £30 million
