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ITEM EX15

EXECUTIVE – 7 SEPTEMBER 2004

Report by the Head of Transport

1. This report:

1. summarises the technical case for and the results of consultation on improvements to the Green Road Roundabout, which was held in May and June 2004;
2. seeks approval to include the development of contract stage for the long term measures in the 2005/6 Capital Programme to achieve a target construction start in spring 2006, subject to adequate funding in the following year; and
3. outlines a procurement route and seeks the retention of Transport Consultants Faber Maunsell as design consultants for the contract procurement and detailed design.
   
   

Background and Technical Case

2. The westbound A40 approach to the Green Road Roundabout suffers from heavy congestion at all times of the day with average queues of approximately 1100 metres forming during the morning peak period. Long queues also form on the southbound A40 and the A4142 Eastern Bypass during morning and evening peak periods.
3. Faber Maunsell have investigated the best form of improvement to the existing Green Road Roundabout. This work was put before the Executive at the 4 March 2003 meeting. The Executive agreed that the long term measures to signalise the roundabout be developed further and consultation undertaken. There are also short and medium term measures, an eastbound bus lane on the A420 London Road approach to the roundabout and traffic signals on the two junctions of Waynflete Road with Bayswater Road. These were approved for implementation by the Transport Implementation Committee on 8 January 2004 following consultation and exhibitions in late September 2003.
4. New traffic surveys were conducted on Thursday 16 and Friday 17 October 2003. These were to establish more robustly what the unsuppressed demand flows were on all approaches of the junction for every day of the week. Additional queue length surveys were also carried out on all five arms of the roundabout during morning, off-peak and evening peak periods. This new survey information was used to remodel the signalised junction proposal prior to the scheduled spring public exhibition on the long term proposal. For this an active VISSIM computer model simulation of the proposed new layout was prepared by Faber Maunsell. The conclusion of this technical assessment is that the signalised ‘throughabout hamburger’ roundabout improves the junction operation significantly at peak times. The junction operates within capacity up to the year 2019.
5. The main reason that the proposed ‘throughabout’ roundabout works is that it allows both (eastbound and westbound) A40 traffic flows to go in the same phase of the signals. The ‘throughabout’ reduces into 3 stages what would have to be a 4 stage signal operation on a standard roundabout. This produces significant capacity improvements which are demonstrated by the computer model.

Consultation

6. The VISSIM model and the other consultation materials were prepared in consultation with the Executive Members for Transport and Sustainable Development.
7. Public exhibitions showing the proposed long term scheme (see Annex 1) (download as .doc file) were organised on 26, 27 and 28 May 2004 and held in areas most affected by the proposed changes, namely Barton, Headington and Risinghurst. Most exhibition materials, including the questionnaire, were also published on the County Council website. The closing date for receipt of comments was 30 June 2004 and Faber Maunsell have analysed all of the qualifying responses and written a report of the findings. The report is in the Members’ Resource Centre with key findings being detailed in paragraph 9 below. A full size drawing showing the long term proposals will be displayed at the meeting.
8. The analysis of all responses generally confirmed the results of the earlier consultation in September 2003 which showed strong support for the proposed improvements. (See Annex 2) (download as .doc file).

Key Findings

9. The key findings of the consultation demonstrate that the majority of local people are convinced of the merits of introducing a signalised ‘throughabout’ to resolve the safety, capacity and operational problems at Green Road Roundabout:

• Nearly three quarters of respondents were in favour of the proposed conversion of the Green Road Roundabout to a signalised ‘throughabout’.
• Two thirds of the respondents were in favour of the bus pre-signal with just under a fifth being opposed.
• Nearly two thirds of respondents were in favour of the temporary closure of Access 1.
• Over three quarters of respondents were in favour of the signalisation of Collinwood Road.

10. Although the bulk of the detail from the latest consultation is given in Annex 2 (download as .doc file) and the background document report by Faber Maunsell, the three main issues related to residential areas immediately affected by the works require comment here in the main body of the report.

Access from Bayswater Road for Barton

11. There are concerns about the queuing on Bayswater Road and that this is exacerbated by significant wider use by non-local traffic. Although a signal phase cannot be provided in the scheme on this exit the overall queuing is predicted to be much lower than at present because phasing of lights on other exists would create sufficient gaps for Bayswater Road traffic to emerge.
12. This view has created some doubt among residents of Barton and therefore it is necessary to give an account of why Bayswater Road cannot be signalised. This is mainly due to the physical road layout and space restrictions of the storage area on the circulating carriageway of the roundabout, opposite Bayswater Road, which would not be sufficient to accommodate even a very small number of vehicles queuing at the stop line. During the red phase for that stop line exit to Bayswater Road would be blocked by those vehicles which would cause grid lock of the whole system.
13. Some clarification can also be made to the proposed pedestrian measures north of the roundabout below Waynflete Road. The existing Pelican crossing on Bayswater Road will need to be repositioned nearer to the roundabout, however a pedestrian phase at the proposed Waynflete Road signals will be provided to maintain a convenient crossing point for students, and enhance the existing provision overall.

Risinghurst Issues

14. It is important to acknowledge the concerns Risinghurst residents have about their own access, servicing of the shops and use of the area by non local traffic. It is predicted that improved performance of the newly signalised roundabout will significantly reduce the need for through traffic to divert through the area. Traffic Management measures developed during detailed design will consider appropriate traffic restraining measures within Risinghurst. While some traffic restraint may be necessary during the road works construction officers consider that there is no need to impose severe restrictions on accessibility for local residents in the long term.
15. There was strong support (76%) for the Signalisation of Collinwood Road, the two gap closures and bus Pre-signal were also supported. This is detailed more fully in Annex 2.
16. The temporary closure of Access 1 is essential during the works and the permanent closure of Access 2 is required to provide the bus pre-signals.
17. There is enough support for the temporary closure of Access 1, but making it permanent attracts less support and the intention is to monitor traffic behaviour on The Roundway and make a decision on permanent closure of this access way once construction works have been completed and traffic levels stablised.
18. The junction with Collinwood Road is currently used as a diversion route when queues ahead at the roundabout are observed. It is also an important access and egress point for residents, however the right turn in and out is hazardous with an accident rate of 10 in the 3 year period 2001 to 2003. New signals would effectively improve the safety of this junction including pedestrian movements across the A40 between Risinghurst and Barton for local schools.
19. The considered view of officers is, however, that the performance improvements of the main roundabout signalisation should be demonstrated before a decision on the signalisation of Collinwood Road is taken.

Quarry Issues

20. There are some Quarry residents who are very concerned about the impact of the construction works on traffic levels through their narrow streets, however the consultation results show that the majority of Quarry residents support the long term proposals.
21. While a permanent traffic calming scheme for Quarry is included in the future OTS capital programme (2007/2008), it is officers’ view that this should be brought forward and progressed independently with the intention of implementing it, subject to consultation, prior to the start of the main work at the roundabout. If additional temporary restraint measures are identified during the consultation process to deal with diverting traffic during construction, these can be included for later removal.

Programme and Procurement of Design and Construction

22. The budget requirement for the final third stage is of the order of £2.386M: see attached Project Appraisal (Annex 3).
23. Following the strong support expressed during the consultation officers recommend that measures are approved for implementation with a construction target start in spring 2006, subject to funding. The construction phase is likely to take 4-6 months due to the sensitivity, complexity and the diversity of specialised teams required to undertake various elements of the work.

Short Term Measures

24. The introduction of a bus lane on the approach to the roundabout from Oxford is scheduled for this financial year. The Legal Orders were published recently and construction should be complete before Christmas.

Medium Term Measures

25. Officers now consider that the traffic signals on Waynflete Road should be completed with the main works provided there are no serious unforeseen delays to the implementation of the long term proposals. The signalised ‘throughabout’ considerably reduces queues on Bayswater Road and eliminates the need for the second set of signals at the northern junction of Waynflete Road with Bayswater Road, which were recommended to protect Wayneflete Road from queue jumping traffic. The local member supports this strategy.

Supervision and Accommodation of Traffic during the Works

26. Supervision of the construction of the scheme will be by our term consultant, Babtie Group, with Faber Maunsell retained in a Project Manager role.
27. The most critical part of the construction of the scheme is the temporary traffic management and minimising delay while achieving the fastest construction time. For this reason early involvement of the contractor will be sought to engage his particular expertise. By having the consultant and contractor working together to produce the detailed design provides the best means of achieving the lowest practical cost, cost certainty, and predictable construction time. This can be awarded within the Contract Procedure Rules by tendering at this preliminary design stage.

Selection of the Scheme Contractor

28. The contractor will be asked to submit a "quality bid" which will concentrate on the method of carrying out the works and a "price bid" based on the works as drawn up at the moment (the design is sufficiently developed for the work to be accurately assessed and priced). The contract award will be made on a combination of quality and price with quality weighted heavily in the evaluation. The cost of the detailed design when finally developed will then be calculated and agreed using the prices the contractor submitted at preliminary design stage. This has the advantage that the price consequences of design decisions are known and the design can be refined to minimise the cost.
29. The initial contract with the contractor will cover fee payments to assist and participate in the design and associated accommodation measures. It will develop the scheme and the start of works tender total based on agreed rates. However the contract will allow the council to withdraw if there are insufficient funds to start construction.

Retention of Scheme Design Consultant

30. Consultants Faber Maunsell have a contract to produce the preliminary design, the stage we are at now, because of their particular expertise in designing complex signal controlled junctions. An extension is needed to carry out the detailed design and project management. Faber Maunsell have submitted a quotation for the additional work and officers believe it is in the best interests of the Council to permit Faber Maunsell to project manage and design the remaining parts of the scheme because the heart of the scheme is the signal control and the inter-relationship of this with the detailed layout of the new roundabout. To hand the preliminary design on to another consultant for development, or to have Faber Maunsell involved only as a specialist signals consultant, makes the design process more complicated, allows for possible loss of control over all design aspects, and risks not having the best solution to handle the traffic through the junction.

Environmental Implications

31. Both early and medium term measures give priority for buses. This will help to promote public transport as an alternative to the private car. The provision of traffic signals at Waynflete Road incorporating pedestrian phases and relocation of the existing Pelican crossing will offer pedestrians controlled crossing points of Bayswater Road linking the two halves of the Barton Estate. The signals at the roundabout will also improve safety and allow the junction to operate effectively for the next 15 years. The bus pre-signal enables buses from London direction to merge safety with general traffic on the approach to the roundabout signals, giving them at the same time priority with negotiation of the new roundabout.

Financial and Staff Implications

32. The total cost of the scheme is £2.636M. £250K has been provided in 2003/04 and 2004/05. A provision of £2.386M will need to be made in future Capital Programme budgets as detailed in the Project Appraisal. The project is being managed by existing staff with Faber Maunsell being retained as designers. Design fees are included in the overall scheme cost.

RECOMMENDATIONS

33. The Executive is RECOMMENDED to:

1. note the outcome of the consultation as summarised in the report and set out in more detail in the report of consultants Faber Maunsell;
2. approve in principle the implementation of the long term measures as detailed on the plan at Annex 1 to the report, with a target construction start in spring 2006, subject to consideration of its inclusion in the Transport Capital Programme following the settlement of the overall Budget and Capital Programme by the Council in February;
3. approve the Project Appraisal attached to the report; and
4. approve in principle the acceleration of the Quarry Traffic Management Scheme to 2005/06 subject to consideration of the necessary adjustment to the Transport Capital Programme in the October 2004 update.

DAVID McKIBBIN
Head of Transport

Background papers: Faber Maunsell report on the latest consultation

Contact Officer: David Clough Tel: Oxford 815743

24 August 2004

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