Case study
The construction of the new roundabout on the M181 corridor into Scunthorpe formed a key infrastructure upgrade to improve traffic flow, safety, and capacity at a strategic gateway into the town.
The scheme required:
The project presented significant logistical and technical challenges, particularly in maintaining operational capacity on a primary access route while constructing high-performance pavement layers to motorway specification standards.
The roundabout and approach arms were constructed using a full-depth flexible pavement design consisting of:
This structure was selected to provide long-term durability under high HGV loading associated with industrial traffic entering and leaving Scunthorpe.
Given the strategic nature of the M181 link, full closure was not permissible during peak hours. A phased construction approach was adopted:
Traffic modelling ensured peak-hour capacity was preserved wherever possible. The works were sequenced to construct the roundabout in segments, maintaining at least one operational carriageway at all times.
The structural foundation of the carriageway comprised full-depth AC32 dense base course, machine laid in regulated bays.
Key considerations:
The base layer was installed during day shifts where possible to maximise productivity and maintain quality control visibility.
Following base course approval:
Binder course tie-ins to live carriageway were typically completed at night to reduce disruption.
The wearing course comprised SMA 10 Thin Surface Course System (TSCS) in accordance with Clause 942 of the Specification for Highway Works.
Benefits of SMA 10:
Final surfacing operations were undertaken under planned night closures to eliminate trafficking over uncured material and to maintain safety.
Given the strategic nature of the M181 link, full closure was not permissible during peak hours. A phased construction approach was adopted:
Traffic modelling ensured peak-hour capacity was preserved wherever possible. The works were sequenced to construct the roundabout in segments, maintaining at least one operational carriageway at all times.
