Milton Interchange Improvement Scheme.

Descriptions

This scheme will provide a ‘hamburger' link at Milton Interchange for traffic from the westbound A4130 heading onto the northbound A34 towards Oxford. The proposal is also to include widening the Milton Park Link, eastbound A4130 and southbound A34 off-slip approaches to the circulatory to 4 lanes.The scheme will require a new structure under the A34 to enable the hamburger link road located within the Milton Interchange Roundabout. The structure will be constructed within the existing embankment of the A34 road and will be a single span bridge with a precast concrete Y beam/in-situ concrete slab deck on contiguous pile wall abutments and wingwalls.The structure will be a fully integral bridge with a skew of 16 degrees and a skew span of approximately 23 m. Although only crossing 2 lanes of road the span is required to accommodate a stopping sight distance on the 40 m radius link road below.As part of the feasibility designs other options for the construction of the structure were considered and discounted. The limited clearances under the existing A34 dictated by the adjacent bridges precluded the use of a jacking solution.The Highways Agency require 2 lanes of traffic to be maintained in each direction on the A34 at all times with a limited number of short term overnight/weekend closures available to complete the bridge construction. The bridge will be constructed in 3 phases to enable the A34 to remain open for the majority of the construction works. Weekend closures will be required to form the longitudinal construction joints in the deck.Overnight road closures will be required for some operations such as piling near to the carriageway traffic lanes, lifting in the precast beams and works to the centre of the bridge where temporary traffic lanes located either side of the works prevent safe access being obtained.On completion of the scheme the Highways Agency will take responsibility for the structure and will play a vital role in ensuring the delivery of this project.