M606 Car Share Scheme
Construction of a Highways Agency developed combined carrier drain and channel is featured within Britain’s first car share scheme.
The £5.3 million initiative 1.7 mile long lane aims to cut the average peak-time journey by eight minutes for drivers using the M606 and M62 between Bradford and Leeds, in West Yorkshire.
The design and build scheme undertaken by Balfour Beatty features an 800mm wide by 950mm deep insitu concrete combined carrier drain and channel slipformed by specialist contractor Extrudakerb. Concrete was supplied by Cemex and the project was undertaken at night under tidal traffic management so as to mitigate any disruption to the traveling public along this busy stretch of motorway. Productivity exceeded 15m3 per hour.
The system is featured within the Design Manual for Roads and Bridges, Part 6, HA113/05 and represents something of a hybrid surface water channel and slot drain.
Like a slipformed slot drain the internal carrier pipe is constructed by slipforming over an inflated tube. All of the inflatable void former used by Extrudakerb to construct both slot drain and combined carrier pipe is provided by Britpave member Interface Developments.
The diameter of the carrier drain is typically 300mm but can be up to 400mm. The overall size of the drain is proportionate to the diameter of the drain and guidance is provided within the design document as to the relationship between drain and product sizes.
Design of outlets and associated works are included within HA113/05.
Combined carrier drain and channel provides a large hydraulic capacity with a narrow footprint making the system particularly attractive where space is limited.
The system should be considered within Active Traffic Management schemes, road widening and adjacent to concrete barrier.