ITEM EX15 DETAILED PROJECT APPRAISAL APPRAISAL NO: H 171 NAME OF SCHEME: New Pedestrian/Cycle Subway, East Side of Cow Lane, Didcot BASIS OF ESTIMATE: Feasibility Study by Network Rail Consultants START YEAR: 2005/6
This project is to provide a new pedestrian/cycle subway under the railway immediately to the east of the existing Cow Lane Bridge. This will restore the two-way flow for cyclists travelling between the town centre, railway station and the Ladygrove estates with segregation for pedestrians. Network
Rail was commissioned in 2001 to look at the various options for providing
a subway. The findings of this report were reported to the Transport
Implementation Committee on 29 May 2003 where a decision was made to
progress the option to tunnel a concrete box parallel to and alongside
the existing railway underbridge. The Didcot Area Transport Study Steering
Group subsequently discussed and supported providing a new subway.
The Didcot to Milton Heights Link Road Stage 2 Phase 1 (DMH2) road scheme was opened to traffic in November 2002 with the existing Cow Lane Underbridge operating under a one-way order allowing vehicular traffic southbound. When approving the One-way Order in May 2001 members were aware of the restriction being place on cyclists and pedestrians using the bridge and resolved to investigate providing additional cycle / footway traffic provision to serve Ladygrove. The existing Cow Lane underbridge provides for a single lane of traffic southbound and a 1.5 metre wide footway. This is not a desirable level of provision and there is no scope for improvement within the existing structure. The new subway would provide good quality segregated cycle and pedestrian facilities, leaving the existing bridge for southbound vehicular traffic. Sustrans National cycle Network Route 5 passes through the existing bridge. The new subway would allow it to be a two-way cycle route throughout its length. The subway will readily connect with the existing cycle/pedestrian network on both sides of the railway promoting increased two-way local cycle trips.
Didcot is one of four towns identified in the Oxfordshire Structure Plan 2011 for major development. Significant commercial development is taking place in the town centre area, Ladygrove is a large area of new housing to the north of the railway and further housing is planned for the west of Didcot south of the railway. Within Didcot, the Oxfordshire Local Transport Plan 2001-2006 (LTP) has a number of objectives directly related to promoting alternative modes of transport, in particular in promoting safer, more pleasant conditions for cyclists and pedestrians. These are being pursued through an Integrated Transport Study. This project is also consistent with policies outlined in the LTP in promoting cycling by providing safe cycle-friendly infrastructure.
During construction it is anticipated that an increase in noise would be experienced in the area. Although passing trains already cause a regular noise the construction will increase the frequency and periods of noise. Noise generation at night will be kept to a minimum. To the south of the railway, space for construction is limited. This will mean the main construction area will be to the north of the railway. This will lead to:
The subway and the cycleway/footpaths running up to it will change the visual outlook of both dwellings and the recreational area. Landscaping will be needed to soften the visual impact and provide some degree of screening. The design of the subway should make users feel safe, with no hidden corners and a good level of street lighting. The completed subway will provide an environmental benefit by encouraging more local journeys by walking and cycling.
The feasibility report produced by Network Rail looked at other options for providing increased cycle/pedestrian capacity. Other options were discounted on the grounds of cost and increased disruption to the railway. Options involving the existing Cow Lane underbridge were both expensive and disruptive to all modes of traffic on Cow Lane during construction. The only alternative subway under the railway is around 500m east of the proposed structure which makes cycle journey times unacceptably long to the areas served by Cow Lane subway.
The design/construction of a tunnelled box culvert under a live railway requires specialist skills only available from a small number of contractors. The contractor would also need to work closely with Network Rail to obtain consents during the design phase and arrange possessions/restrictions during construction. It would best be procured as a Design and Build Commission.
The Network Rail feasibility report estimated the costs based on historical data as £1.95m with +/-30% accuracy. Assuming an upper band figure and allowing for professional fees the scheme cost is estimated at £2.8m. A detailed resource appraisal is attached. This project forms one element of the Didcot ITS and will be funded by a mix of developer funding and Credit Approval. There will be an ongoing maintenance fee due to Network Rail to be funded from revenue to cover future maintenance and eventual replacement of the subway. Subject to negotiation with Network Rail this may be able to be paid as a commuted sum.
The majority of the land required for this project is in the ownership of either Network Rail or Oxfordshire County Council. The only land where ownership is not known is to the north of the railway and currently is open ground. Steps are being taken to establish the ownership of this land.
The programming of this project is dependent on Network Rail being able to make speed restrictions and short term possessions available. In preliminary discussions with their Outside Parties Engineer the earliest start date would be in financial year 2005/6 with design work taking place in 2004/5.
CHRIS
GRAY October 2003
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