Seven 150-metre sections of the B1099 Upwell Road in March, Cambridgeshire, are being rebuilt using different repair methods. The aim is to find which holds up best on roads built on peat. The trial costs £1.5 million and is funded by the Cambridgeshire and Peterborough Combined Authority.
Each section will be monitored for at least 12 months to gather data for future investment decisions. Winvic Construction Ltd is the contractor delivering the works.
Peat challenges road construction and repair
Peat moves and settles, causing roads above it to crack, sink and break up faster than those on firmer ground. Repairs often require deeper reconstruction and cost four to five times more than standard maintenance. Cambridgeshire County Council says peat-affected roads last less than half as long as others.
About 40% of Cambridgeshire is underlain by peat, including nearly all of Fenland and large parts of East Cambridgeshire and Huntingdonshire. More than 1,800km of the county’s roads are built on these challenging soils. Councillors link the problem to the council’s £800 million maintenance backlog.
Seven distinct repair techniques
The council and contractor chose seven different methods to test side by side on the Upwell Road. These include:
- a control section built with the current repair method
- deep soil mixing, where binding agents are blended into the peat beneath the road to stiffen it
- chemical stabilisation to treat the subgrade
- reinforcement with steel mesh within the road structure
- a cellular confinement system that spreads traffic loads
- resin injection drilled into the carriageway in a grid pattern
- use of alternative lightweight materials to reduce load on the peat
Building these different methods side by side means each faces identical traffic, ground conditions and weather. Differences in performance can therefore be attributed to the repair method itself.
Suitable location for a representative trial
Upwell Road carries heavy and agricultural traffic typical of rural routes across peat soils. The road was due for renewal, making it a practical site for the trial. Councillors and officials, including Cambridgeshire and Peterborough Mayor Paul Bristow, visited the site on 8 October alongside the council project team and Winvic framework manager Andy Harmon.
Alongside the trial, the council resurfaced Upwell Road between the roundabout with Cavalry Drive and Binimoor Road as part of wider repair efforts ahead of winter.
Implications beyond the trial
The council currently receives no extra funding to cover the higher cost of maintaining roads on peat. If one repair method clearly outperforms the others, funding that approach across 1,800km of peat roads will be challenging.
For other UK councils with peat soils, including Norfolk and Lincolnshire, the trial’s findings will inform future maintenance strategies.
