A428 Black Cat to Caxton Gibbet Improvements
MI Engineers provided cost engineering for the A428 upgrade, a new 19km dual carriageway improving traffic flow, safety, and growth. The £900M project reduces congestion in the East of England.
The problem:
The A428 between St Neots and Caxton Gibbet is the only remaining stretch of single carriageway between the M1 near Milton Keynes and Cambridge, causing significant congestion and delays, particularly during peak hours. This road serves as a crucial link between major communities, and with projected local housing and job growth, traffic volume is expected to increase by 30% by 2040. The lack of alternative routes exacerbates the problem, leading to increased traffic on local roads and negative environmental impacts. The challenge was to develop a solution that would reduce congestion, support economic growth, and improve safety and environmental conditions.
The solution:
The proposed solution was to upgrade the A428 by constructing a new 19km dual carriageway between the BlackCat and Caxton Gibbet roundabouts. This upgrade would significantly improve travel times, reducing journey times by more than a third during peak hours, and enhance road safety and capacity. Additionally, the project aimed to support regional economic growth, reduce congestion on local roads, and improve environmental conditions by maintaining biodiversity and improving air and noise quality. The new dual carriageway also planned to include safe crossing points for walkers, cyclists, and horse riders, thereby enhancing travel options for all road users.
What did MI Engineers do:
- Conducted all early-stage capital works estimates to identify the best-performing solutions.
- Refined estimates throughout the optioneering and development stages, supporting preferred route decisions, public consultations, Development Consent Order submissions, and the client’s business cases.
- Developed long-term operation and maintenance estimates to inform the economic assessment for Benefit to Cost Ratio calculations.
- Established the client’s budget for market engagement.
- Led budget negotiation activities with the preferred supplier to secure a contract agreement satisfactory to both parties.
- Produced the final estimates for use in the client’s Final Business Case.
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