M25 Drainage Renewals

Constructing Excellence

Connect Plus holds the 30 year DBFO (Design, Build, Finance, Operate) contract for maintaining, operating and upgrading the M25 motorway on behalf of National Highways. Comprising 440Km of motorway and arterial link roads around London, the M25 is one of the busiest road networks in Europe, playing a pivotal role as the hub of National Highway’s Strategic Road Network, supporting journeys in and around London and connecting customers with other parts of the UK.

Along with the maintenance of large assets such as the Dartford Crossing, the DBFO contract also involves maintaining thousands of smaller assets such as gantries, technology devices and drainage systems.

In 2021, Connect Plus asked Jackson to undertake a drainage survey which involved inspecting, repairing and replacing, where necessary, 1050 individual manhole covers across the network. A seemingly straightforward task, however, a number of challenges were involved that have been solved by the use of digital technology.


Three Winning Facts:
  1. By integrating these two digital assets, the team were able to exploit every possible opportunity and shared 242 existing closures, reduced risk to the workforce by saving 36,000 additional person-hours on the net work and generated a direct financial saving of £445,675 in reduced traffic management costs.
  2. As the project progressed, the team were able to identify clusters of defects. With further investigation, this has enabled them to identify the causes, such as original methods of construction, or different ground conditions. This helped inform the budgets for the remainder of the project and has also provided the teams with valuable insight into future maintenance schedules. For example, if the data shows that manhole co-vers on concrete sections of road are more likely to fail in the future, Connect Plus can adjust its future maintenance schedules to account for this.
  3. The Power BI dashboard made real-time data available to the client without placing an additional administrative burden on the delivery team