This project was for the upgrade and widening of the existing carriageway into a dual carriageway on London Road, Biggleswade.
This involved a full depth flexible construction which included the construction of a new roundabout; earthworks; installation of new storm and foul water deep drainage systems; kerb ACO drainage; installation of precast concrete kerbing, tactile paving and edge paving; cold milling and regulation; BT, HV, LV and Virgin Media diversions; traffic signal and LV ducting; street lighting ducting and DNO supplies; traffic signal installation for two pedestrian crossings; street lighting and signage; Anglian Water connection works; traffic management; material testing; thermoplastic road markings and topsoiling.
During the installation of both the storm and foul drainage, we encountered in excess of 675 service interfaces with existing services, which caused us to be flexible with our shoring methods and reduced outputs due to invert conflicts and interfaces as deep as 4m. We were required to keep two-way traffic flowing at all times and with over 5.1 million vehicle movements and 27,000 pedestrian movements through our works this proved challenging. The regulating course was installed with limited space due to the traffic management restrictions.
Some of the lessons learnt and improvements we made during the scheme were undertaking the surfacing works overnight within full road closures to minimise disruption during peak hours. The need in the future to review drainage output expectations because of the service interface and shoring difficulties due also to service interface.