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Madingley Road / A428 Corridor Study Options Appraisal Report Cambridgeshire County Council 20 June 2014

Transcript of Madingley Road / A428 Corridor Study Options Appraisal Report · 6/20/2014  · Madingley Road /...

Madingley Road / A428 Corridor Study Options Appraisal Report Cambridgeshire County Council

20 June 2014

Madingley Road / A428 Corridor Study Options Appraisal Report

Atkins Options Appraisal Report | Version 1.0 | 20 June 2014 | 5131840

Notice This document and its contents have been prepared and are intended solely for Cambridgeshire County Council’s information and use in relation to the Madingley Road / A428 study.

WS Atkins Ltd assumes no responsibility to any other party in respect of or arising out of or in connection with this document and/or its contents.

Document history

Job number: 5131840 Document ref:

Revision Purpose description Originated Checked Reviewed Authorised Date

Rev 1.0 First draft EM SA GGH NC 20/06/14

Rev 1.1 Further option definition (ph2)

EM SA GGH NC 21/08/14

Client signoff

Client Cambridgeshire County Council

Project Madingley Road / A428 Corridor Study

Document title Options Appraisal Report

Job no. 5131840

Copy no.

Document reference

Madingley Road / A428 Corridor Study Options Appraisal Report

Atkins Options Appraisal Report | Version 1.0 | 20 June 2014 | 5131840

Table of contents

Chapter Pages

Executive summary 5

1. Introduction 8 Context 8 This study 8

2. Problems and challenges 9 Introduction 9 Weaknesses and threats 9 Strengths and opportunities 13 Summary 14

3. Objectives and outcomes 15 Introduction 15 Intervention objectives 15 Geographic area of interest 16

4. Option identification and sifting 18 Introduction 18 Element identification process 18 Long list of options identified 19 Option packaging process 21 Initial option sifting process 21 Second assessment process 23 Deliverability 23 Benefits / impacts 24 Recommended options 28

Tables

Table 4-1 Long list of elements identified, and main variants 20 Table 4-2 Preferred packages following initial option sift 22 Table 4-3 Engineering cost and timescale summary 24 Table 4-4 Modelling results summary 26

Figures

Figure 2-1 Morning peak 3 hour demand, all modes, 2031, ‘do something’ Scenario K with transport improvements (flows over 100 people shown) 11 Figure 3-1 A428 Western Corridor Study Area 17 Figure 4-1 Option process flowchart 18 Figure 4-2 Option compatibility matrix 21 Figure 5-3 Demand-based option assessment process 27 Figure 4-4 Scheme A 30 Figure 4-5 Scheme B 30 Figure 4-6 Scheme C 31 Figure 4-7 Scheme D 31

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Executive summary

Approach

Phase 1 of the A428 Western Corridor Study involved the initial assessment of options designed to fulfil the criteria outlined in the project brief, consideration of demand and option feasibility and ultimately an assessment of the options against an agreed framework in order to generate a shortlisted option set for further consideration and assessment in Phase 2. This Options Assessment Report presents the findings from this phase of the study, outlines the methodology of the project and presents the options considered thus far.

The options packages were generated and refined through a series of workshops and assessments to ensure the process was thorough and considered a range of factors, which can be summarised as:

an initial brainstorming and package generation process, in which 21 individual elements were combined to generate 34 packages;

an initial sifting process involving refining the grouping of the elements into options followed by further analysis and sifting;

a workshop during which the options underwent further evaluation, and three additional options were subsequently added to the shortlist; and

a more detailed option assessment process which ultimately sifted the shortlist down to five recommended options.

This study has identified the problems and challenges of the A428 corridor, and established the planning objectives that any interventions should achieve before proceeding to option generation and assessment. This allowed a deep understanding of the characteristics corridor to be obtained before deriving any solutions.

The study has shown that the A428 corridor suffers from congestion, poor journey times, and poor journey time reliability during peak hours. The evidence shows that these problems are focused on specific sections of the corridor, particularly on the A1303, east bound into Cambridge and, to a lesser extent, on the section of the route between St Neots and Caxton Gibbet (A428 / A1303 junction). Planned growth along the corridor, specifically at Cambourne, Bourn Airfield, and St Neots will, in future, add extra pressure onto already congested sections of the A428 as residents access employment sites in Cambridge City Centre, Cambridge Science Park, and Addenbrooke’s hospital. The evidence is clear that the A1303 cannot physically accommodate any more vehicular traffic during the morning peak hour and there is a danger that the current queue could extend onto the dualled A428, having an adverse impact on the fast journey times associated with this section. The problems on the A428 corridor present a significant constraint to achieving the levels of planned growth in the county.

Planning policy has determined that key radial routes into Cambridge that are targeted to deliver growth, including the A428, need to cater for additional journeys using more sustainable modes of transport which include public transport, walking and cycling. The TSCSC, developed to support the current Local Plan review, outlines major investment in public transport as a pre-requisite to support employment and housing growth at key development sites along the A428. The objective is to deliver high quality passenger transport service, complemented with cycling and pedestrian routes, along the corridor to link sites for housing growth with key employment sites, primarily in Cambridge. The ambition is to deliver an equivalent standard of public transport provision in terms of reliability, frequency and speed to the Cambridgeshire Guided Busway. The use of multi-criteria analysis, engineering and modelling expertise, and professional judgement has sifted a long list of into a short list of four options that meet high level criteria under strategic rationale, deliverability, and benefits / impacts, and which have the greatest potential to meet the key objective of:

Congestion free public transport serving the corridor including new developments, in order to avoid an increase in current congestion levels and public transport journey times.

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Shortlisted options

The work outlined above indicates that there are a number of potential solutions that have the ability to achieve the objectives of the scheme. Five packages have been assessed as best achieving these objectives and therefore have been shortlisted for further detailed assessment during Phase 2 of this study. Some of the options to be taken forwards are derivatives of those which have been tested thus far, while others still have some refining to them that will take place throughout Phase 2. The options that are to be taken forwards are:

Option 3 (Park & Ride at Caxton Gibbett, a segregated bus route via Cambourne and Bourn Airfield re-joining Madingley Rise just west of the M11, and an eastbound nearside bus lane on Madingley Road);

Option 5 (Park & Ride at Madingley Mulch, signalisation of Madingley Mulch roundabout, a nearside eastbound bus lane on Madingley Rise and Madingley Road);

either Option 7 (a segregated bus route through Cambourne and Bourn Airfield, with services then running via a new junction with the A428 to Madingley Mulch roundabout, signalisation of Madingley Mulch roundabout, a nearside eastbound bus lane on Madingley Rise and Madingley Road, potential intermediate Park & Ride at Bourn Airfield); or Option 8 (as Option 7, but alternatively running via St Neots Road rather than tha A428);

Option 10 (a segregated bus route via Cambourne and Bourn Airfield re-joining Madingley Rise just west of the M11 having run to the north of Madingley Rise from Madingley Mulch (note this is a modification of the previous Option 10 which assumed a new M11 over bridge), nearside eastbound bus lane on Madingley Road); and

either Option 7 or Option 8 plus Option 11 (Park & Ride at Madingley Mulch, segregated offline bus route south of Madingley Rise and Madingley Road).

Each option has a number of different benefits that it can provide, although there are also recognised dis-benefits associated with each option. A summary of these can be found in Appendix E.

Since all options considered at this stage are estimated to cost in excess of £20m, a low cost alternative has not emerged from the study so far. Further work will be undertaken in Phase 2 of the project to agree the “do minimum” and LCA options with the client.

Next steps

The key objective of phase 2 of the project will be to develop the shortlisted options (including the “do minimum” and LCA) and undertake further appraisal to produce robust evidence which will support the preparation of the outline business case.

Key activities of phase 2 will include:

establishing the “do minimum” and “do something” scenarios in greater detail;

carrying out feasibility scheme design and cost estimates;

producing an Appraisal Specification Report;

testing of the shortlisted options using CSRM, having established an appropriate do minimum scenario in the model;

assessing in detail the impacts of the shortlisted options; and

producing an Outline Business Case, non-technical summary and a developer funding technical note

In addition, phase 2 will provide the opportunity to consider recommendations from project workshops and other issues uncovered during phase 1 of the project which warrant further investigation. These include but are not limited to:

achieving greater detail on route alignments, for example, understanding the potential for using land between St Neots Road and the dualled A428 for a segregated bus route;

consideration of specific engineering solutions to address corridor issues, for example, necessity of structures spanning major roads or whether it would be more beneficial to signalise Madingley Mulch Roundabout or transform it into a ‘hamburger’ roundabout;

the environmental impacts of off-line options;

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understanding funding sources for different options, including developer funding and other potentially innovative funding opportunities and hence affordability;

phasing and triggers for options, for example, at what level of growth in housing and jobs do option(s) need to be implemented in order to meet the stated objective; and

greater understanding of the potential impact of recent planning decisions, for example, the relocation of Papworth Hospital to Addenbrooke’s and the change of use of the current hospital site and its impact on the local road network.

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1. Introduction

Context

1.1. Greater Cambridge city region1 is one of the fastest growing parts of the UK; with the population growing by 14% to over 270,000 by 20112. This high rate of growth is expected to continue; the Cambridge City and South Cambridgeshire Local Plans (both currently at examination stage) envisage further population growth up to 2031 of 33,000 new homes (equating to a 25% rise in population) and 45,000 new jobs.

1.2. This level of employment growth is fuelled by the ‘Cambridge phenomenon’ – an agglomeration of high-tech and research-based economic activity currently employing over 50,000 people in Cambridge which is expected to continue to grow rapidly. The success of this sector in Cambridge can be attributed to three factors, one being the scale and connectivity of the city.

1.3. However, it is recognised that the levels of growth envisaged in the Local Plans will require good connectivity and additional capacity for travel between new and existing residential and employment areas. The City Deal Transport package, which builds on the Transport Strategy for Cambridge and South Cambridgeshire (TSCSC), sets out an integrated, multi-modal programme to support this growth. The package focuses on improving connectivity, especially to new residential areas outside the city boundary. Given the desire to continue to improve the quality of life in Greater Cambridge, and that the existing highway network is at or near capacity for much of the day, the package focuses on public transport, cycling and walking solutions.

This study

1.4. This report is the first output from a study which will identify and assess options for improved public transport, walking and cycling facilities on the Madingley Road / A428 corridor3. This is the first corridor to be studied in detail, and was selected due to the large-scale development envisaged in the Local Plans in this corridor, in particular at Cambourne and Bourn Airfield. Phase One of the study (which is reported here) has involved a high-level assessment of potential options and selection of a short list of potential solutions to be carried forward for more detailed assessment in Phase Two.

1.5. The planned growth in the corridor has the potential to add to the, already high, levels of congestion in and around Cambridge. On the A428 corridor there are a number of areas where increased traffic levels would have significant detrimental effects, particularly Madingley Rise and Madingley Road. Current conditions on these roads in the morning peak are undesirable, with up to 80% of the length of these routes subject to queuing, with delays up to 18 minutes. One aim of this scheme therefore is to ensure that the current congestion levels on Madingley Rise are not any worse in the future than they are today.

1.6. The key challenge is therefore to identify ways to ensure that this growth does not worsen the existing situation but, ideally, how measures can be put in place to improve connectivity and the quality of the environment in Greater Cambridge. Any proposed solution must therefore be able to offer those wishing to make trips (both those already existing and future trips to/from new developments) desirable and high quality alternatives to traditional car-based highway trips.

1.7. The key aim of the study, as defined in the brief, is therefore to identify ways of:

Providing a congestion free public transport scheme serving the corridor including new developments, in order to avoid an increase in current congestion levels and public transport journey times.

1.8. Phase One of this study was conducted during April, May and June 2014.

1 The area covered by the districts of Cambridge and South Cambridgeshire. 2 2001 and 2011 Census. 3 The study will focus on the section between Caxton Gibbet and Cambridge but will also consider options for the section between Caxton Gibbet and St Neots.

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2. Problems and challenges

Introduction

2.1. This chapter describes existing and future problems and challenges relating to transport on the A428 / Madingley Road corridor. Problems and challenges have been identified and, where possible, quantified, based on available information, data and model runs, including:

current planning and transport policy documents;

National Census information from 2001 and 2011;

transport data, including traffic flow, public transport provision, road safety and journey time information; and

forecasts of travel demand from transport data from existing Cambridge Sub Regional Model runs.

2.2. The information below is a summary of the findings, with the table in Appendix A.5 (page 23) giving a full picture of the analysis.

Weaknesses and threats

Current problems and challenges

Traffic volume, congestion and delays

2.3. Current conditions on the highway network are known to be variable along the length of the corridor. Analysis of TrafficMaster speed data showed that there is high reliability and limited congestion along the dual carriageways section of the A428, providing a high quality route for car users. Currently this section of the route caters for up to 2,200 vehicles per hour in the morning peak travelling towards Cambridge and up to 2,100 vehicles per hour westbound in the evening peak.

2.4. In contrast, there are know congestion issues at either end of the corridor, with the A428 between Caxton Gibbet and St Neots shown to have high variability and congestion, with delays of up to 10 minutes eastbound in the morning peak and 3 minutes in the evening peak period. This is caused in part by the upstream junctions (A1198 / A428 junction when travelling eastbound, the junctions to the east and south of St Neots when travelling westbound) and in part by the capacity constraint of the road itself, which is currently catering for up to 700 vehicles per hour each way in the morning peak, and 800 vehicles per hour each way in the evening peak.

2.5. The A1303 approach to Cambridge is shown to have greater levels of variability and congestion, with delays of up to 18 minutes travelling in to Cambridge in the morning peak, and 4 minutes travelling westbound in the evening peak. The problem can be seen to propagate from the combination of two significant traffic streams at the A1303 / M11 junction as well as downstream junctions entering Cambridge itself when travelling eastbound, with up to 80% of the route experiencing queuing in the morning peak. A further factor is the interaction of traffic entering and leaving the well used Madingley Road Park & Ride site, with the signalised junction here contributing to variability and delay. This combination of different streams of traffic leads to the greatest level of flow between M11 junction 13 and the Madingley Road Park & Ride Site, with peak direction traffic flows of up to 1,200 vehicles per hour.

2.6. The outbound direction is less significant, with congestion developing from M11 junction 13 back towards Cambridge.

2.7. The key aspects can be summarised as:

there is a significant peak in eastbound A1303 traffic flow at the Madingley Road P&R site;

there is significant journey time variability along the single carriageway sections of the corridor, particularly eastbound in the morning peak and westbound in the evening peak

this results in low traffic speeds in both peaks, particularly approaching / at key junctions;

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during AM peak 80% of route length from A428 / A1303 junction to M11 J13 is subject to queues;

the average delay in AM peak is 18 min between A428 / A1303 junction and Queens Road / Northampton Street, with the average delay in AM peak being 10 min between St Neots and Caxton Gibbet; and

there is a significant knock on impact of interaction between P&R, M11 and other traffic that exacerbates congestion.

Road safety

2.8. Analysis of road accident data between 2009 and 2013 shows that the accident rates are similar to national averages. However it was noted that there were two sections of the corridor that exhibited a greater number of accidents during the five year period.

2.9. The section of the A428 between Eltisley and Caxton Gibbet had a total of 37 accidents in the five year period, comprising 27 slight and 10 serious incidents. No incidents were fatal during this time. This area correlates with an area of congestion as analysed above.

2.10. The other section of note was the A1303 between the A428 and M11 with a total of 30 accidents reported, comprising of 22 slight, 6 serious and 2 fatal accidents in the five year period. Once again, this area is one that has been highlighted as one of acute congestion, particularly in the morning peak.

2.11. It should be noted that there was on average only 1 accident per year involving a pedal cycle on the route. This could indicate that there is currently limited levels of cycling along the route.

Public transport provision

2.12. Current public transport provision along the corridor is limited, with only two services running between St Neots and Cambridge in the morning peak hour and seven services running from Cambourne to Cambridge within the corridor during the morning peak hour.

2.13. The service from St Neots to Madingley Road is timetabled to take 30 minutes, which compares to the average journey time by car of 37 minutes (based on TrafficMaster).The service from Cambourne to Madingley Road is timetabled to take 31 minutes, which compares to the TrafficMaster journey time of 20 minutes by car.

2.14. Cambourne is currently served best within the corridor with a number of services either starting or passing through to destinations both on and off the corridor. There is limited service for the number of smaller villages along the corridor, with some locations (such as Toft and Caldecote) only receiving a daily service into Cambridge.

2.15. These wider services are supported by a Park & Ride site on Madingley Road close to M11 Junction 13, which has shown consistent growth in patronage. Recent surveys suggest that the site captures up to 45% of in scope traffic passing the site. There are however difficulties in accessing the site due to the existing congestion on the adjacent highway network.

2.16. A key factor that may be a barrier to improved services in the corridor is the lack of priority for bus services, with a short bus lane on the approach to M11 junction 13 being the only significant measure along the corridor. Public transport therefore is able to offer little significant journey time benefit compared to car travel on the highway network.

Pedestrian and cyclist facilities

2.17. Walking and cycling provision is provided locally to Cambridge, including off-road routes to Coton and between Hardwick and Caldecote, however these does not extend along the entire length of the corridor, meaning that there is no connection between the new development sites and Cambridge. There is the potential to walk or cycle along St Neots Road, although may still not be desirable without any dedicated cycling provision. Currently there is non-continuous provision along the corridor, although it must be considered that the length of the route may preclude travel for slow modes along the entire length.

Car ownership and use

2.18. The area under study is subject to high car ownership, with the 2011 Census reporting 85% of households owning a car (compared to the national average of 74%), with 42% owning more

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than one car. This high car ownership is supported by high levels of employment, with an unemployment figure of 2.3% compared to the national average of 3.2%, with a bias towards highly skilled occupations.

2.19. There are a number of key employment areas within Cambridge City Centre including the University of Cambridge as well as those on the outskirts of the City such as the Cambridge Biomedical Campus at Addenbrookes and Cambridge Science Park. Journey to work data demonstrates that there is a high tendency towards car as the dominant mode of choice, with around two-thirds of journeys to work made by car. Bus usage is typically 5% of lower, with walking and cycling comprising less than 10% of the total journeys made to work.

Land use and environmental constraints

2.20. There are a number of varied land uses along the corridor, each of which may have an impact on any proposed public transport scheme in the corridor. There are a number of Sites of Special Scientific Interest as well as other physical constraints such as the Madingley American Cemetery and Barton Firing Range Safety Zone in the corridor that need to be considered for any proposed schemes.

2.21. Further details are provided in Appendix A.2.

Future problems and challenges

Housing and employment growth

2.22. The Cambridge City and South Cambridgeshire Local Plans (for examination) envisage significant growth in housing and employment in the corridor including:

3,500 new homes at the Bourn Airfield (1,700 by 2031);

1,200 new homes at Cambourne West;

3,700 new homes plus 25 hectares of employment at St Neots;

2.23. There is also policy driven growth within Cambridge, both in terms of housing and employment. 15,000 new jobs are planned for Cambridge Biomedical Campus, Addenbrookes which will also house the relocated Papworth Hospital. The campus will eventually have a working population of around 30,000, making it one of the largest biomedical sites in the world. Further employment growth is likely to continue in areas such as Cambridge Science Park, as the Cambridge Phenomena continues to take hold

2.24. North West Cambridge (up to 2,500 new homes) and Darwin Green 2 (approximately 1,100 new homes) will also contribute to residential growth within Cambridge, with the potential to put more strain on the transport system.

Travel demand

2.25. Underlying increases in demand for travel, for example due to economic growth nationally, and local growth in demand due to the development described above are forecast to lead to substantial growth in the demand for travel in Greater Cambridge.

2.26. At this stage of the study, these forecasts are based on existing runs of the Cambridge Sub Regional Model (CSRM) for the South Cambridgeshire Local Plan (Scenario K) and therefore reflect the assumptions made in preparing those forecasts. As CSRM is a land use-transport interaction (LUTI) model, the travel demand forecasts it makes are influenced by assumptions about available development land; and the transport networks and services available. As the ‘do something’ scenario does not assume the level of public transport provision in the corridor anticipated to arise from this study, but does assume the dualling of the A428 between St Neots and Caxton Gibbett, it is reasonable to assume that the forecast underestimates the demand for travel to and from Cambridge, and overestimates the demand for travel to and from St Neots.

2.27. Figure 2-1 below summarises the forecast demand for travel in the corridor in 2031.

Figure 2-1 Morning peak 3 hour demand, all modes, 2031, ‘do something’ Scenario K with transport improvements (flows over 100 people shown)

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Traffic conditions

2.28. The CSRM runs analysed forecasts that car trips on the A428 corridor towards Cambridge will increase by 45% in the morning peak hour; 70% in the inter-peak period; and 50% in the evening peak period4 between 2011 and 2031. However, the model also predicts that traffic flow levels on Madingley Road would remain relatively unchanged in the morning peak as the road is already at capacity and therefore unable to accommodate additional traffic. This would result in additional queuing as well as applying additional pressure to other routes in to Cambridge.

2.29. This increase in demand will have a negative impact to travel conditions on the highway network, including:

Worsening congestion – without intervention it is expected that congestion in the corridor will increase. Madingley Rise is currently at saturation point in morning peak, so queues would get worse on upstream sections with adverse impacts on journey times and accidents rates. This will make it more difficult to provide reliable public transport services that utilise the highway network without any priority for public transport.

Peak Spreading – as congestion worsens some peak spreading could be expected in the morning and evening Peaks. With more flexible working arrangements it is possible for journeys to work to take place before or after the traditional AM peak hour between 08:00-09:00; the PM Peak can be expected to be more spread out then at present, and it tends not to coincide with education trip peaks. This will prolong the peak congestion periods, lengthening the time for which traditional public transport services will be exposed to increased congestion levels effecting service quality and reliability.

Internalisation of Bourn and Cambourne – in the absence of good transport links predictions show that the majority of the population of Bourn and Cambourne will choose to work locally or travel to work by car. In the case of Bourn, lack of external transport connectivity will limit growth, with model data forecasting that only 85% of households will form within the development.

High levels of car ownership – in the absence of high quality public transport the model predicts that car will be the dominant mode of transportation, with most of the households forming in Bourn and Cambourne having high levels of car ownership.

2.30. There are a number of other threats that could materialise to a greater or lesser extent over the coming years. The travel patterns into and within Cambridge are likely to become more diverse as the employment areas expand over a wider area, creating less focus for trips into the City.

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This creates a challenge to provide a high quality service to key destinations if these become more disparate.

2.31. The growth that is likely to occur adjacent to Madingley Road will also become more difficult to serve, particularly by Park & Ride means. This could lead to an increased reliance on car trips to this area, putting greater pressure on the highway network. Another factor that may increase pressure on the highway network is the A14 Cambridge to Huntingdon improvement, which may create easier access to Cambridge, promoting the greater use of car as a transport method to access the City.

2.32. Should development to the south of the City also intensify, these areas are currently not served well by public transport, and are limited in their potential due to a lack of potential routes that can be utilised to provide a high quality service.

Strengths and opportunities

Strengths

2.33. While there are a number of weaknesses in the corridor, there are some key strengths that can be taken advantage of for any future scheme:

The existing Park & Ride site at Madingley Road has a high capture rate of 45% of trips in scope, indicating that there is already a strong appetite for utilisation of Park & Ride services, particularly to access the City Centre employment sites.

The dual carriageway of the A428 is an existing high quality piece of highway infrastructure that has the ability to serve an increased number of highway trips from growth areas, although provision to enable these trips to access Cambridge needs to be ensured.

There is existing cycle provision along some sections of the corridor, however it is noted that this is not continuous along the entire length.

Opportunities

2.34. The aspiration to improve public transport, walking and cycling measures in the corridor is fully supported by current policy, including the Local Plan (which sets out the objective for high quality segregated bus priority measures on the A1303 between its junction with the A428 and Queens Road), the TSCSC and Greater Cambridge and Greater Peterborough Strategic Economic Plan.

2.35. Surveys of those currently driving on Madingley Road, and the CRSM forecast shown in Figure 2-1above indicate that whilst travel patterns are fairly dispersed, there are some dominant travel desire lines now, and in the future. In particular, a significant proportion of demand is to/from central Cambridge5 and Cambridge Science Park. Forecast demand between Cambourne / Bourn Airfield and St. Neots is also high, and will be the subject of subsequent study.

2.36. While the current high levels of congestion on areas of the highway network is undesirable, this does give an opportunity for a public transport scheme that can bypass these areas of delay and unreliability to provide a real benefit and high quality alternative to car travel – peak journey times between the A428 / A1303 junction and Queens Road are currently three times those in the inter-peak, meaning that there is an opportunity for public transport to offer a quicker journey than comparable trips by car.

2.37. Whilst there are some constraints, there is also scope for construction within the highway boundary at a number of locations, as well as potential for use of the old A428 (St Neots Road) as either a dedicated bus route or to improve walking and cycling facilities in the corridor. As the Bourn Development and the Cambourne West expansion have not yet progressed to planning stage, there is potential for safeguarding off-line route alignments before growth takes place.

2.38. Taking a wider view, there are also opportunities to provide a number of solutions from Cambourne and Bourn that are away from the alignments of both the A428 and A1303. While there are constraints that need to be worked around, there are a number of options to provide a new dedicated route. Land is currently available and the opportunity exists to provide a balanced

5 28% of morning peak car trips surveyed by the Madingley Road RSI were destined for central Cambridge.

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solution for the transport network and the nearby communities through high quality bus priority measures.

2.39. There is also scope for a new Park & Ride site located further west from Cambridge than the existing site on Madingley Road. This would provide the opportunity to capture trips from both the new developments along the corridor as well as the existing demand that uses the A428, and intercept it in advance of the area of acute congestion along the A1303.

2.40. Along the A1303 itself, there are options to bypass, or expand the current highway within the existing highway boundary, which gives a range of different solutions that could be investigated.

Summary

2.41. The high car ownership and Cambridge-focussed employment that is currently in evidence along the corridor means that there is likely to be increasing congestion on the approach to Cambridge. This high car ownership allied to limited high quality public transport provision means that there is a high proportion of journey to work trips made by car, with limited alternatives giving rise to congestion on the approach to Cambridge.

2.42. Current congestion experienced along the corridor is high, resulting in poor travel conditions for all modes of travel. These conditions are forecast to get worse over time, as new developments and continued growth takes place along the corridor. These growth areas currently have poor connections by public transport, and therefore there is little realistic alternative to car travel at this time, which would put unacceptable levels of additional traffic and therefore congestion on the highway network. This would not fall in line with the long term vision of Cambridge Count Council for a better quality of life within the Sub Region. Therefore, it is not possible to realise the development and growth aspirations of the Local Plans without interventions to facilitate desirable and realistic alternative to travel by car through the provision of high quality public transport services between key locations.

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3. Objectives and outcomes

Introduction

3.1. The previous chapter summarises the problems and challenges in the corridor and how they will become more acute without intervention. These issues provide a ‘bottom up’ and reactive perspective to identifying potential solutions.

3.2. In this chapter, a set of outcome-focussed ‘planning objectives’ are defined which offer a ‘top down’ perspective to the option identification. Specifically, the planning objectives set out what the proposed interventions are intended to achieve in terms of measurable outcomes. As well as informing the option identification process, the planning objectives also form a key element of the assessment framework used to sift options and identify those for further consideration in Phase 2.

3.3. In this chapter the geographical scope of the potential interventions is defined.

Intervention objectives

3.4. The planning objectives for the study were derived based on the project brief, the team’s understanding of what the solutions needed to achieve and high level goals and strategic objectives identified in policy documents.

3.5. Strategic objectives for intervention are set out in a number of policy documents including the Draft South Cambridgeshire Local Plan, Draft Cambridge City Local Plan, Draft Transport Strategy for Cambridge and South Cambridgeshire, Huntingdonshire Draft Local Plan, and the National Planning Policy Framework.

3.6. The following high-level objectives are specified in the policy documents and represent the transport outcomes required by any option. Some of these objectives are outcomes (highlighted) whilst others relate to potential ways of achieving those outcomes. They are:

to maximise potential for journeys to be undertaken by sustainable modes of transport including walking, cycling, bus and train [outcome];

to provide bus based high quality public transport corridor long the A428 connecting Cambridge and St Neots;

to provide high quality segregated bus priority measures on the A1303 between its junction with the A428 and Queens Road, Cambridge;

to provide improved East West rail links and access along the A428, A47 and A14, will enhance economic growth opportunities and connectivity with Milton Keynes, Oxford, Luton & Bedford and the East Coast Ports; and

to support growth, help create jobs and housing, locate growth in locations that minimise the need to travel and maximise the use of sustainable modes [outcome].

3.7. The planning objectives were agreed at a workshop with Cambridgeshire County Council. They are to provide high quality public transport which:

serves key current/future trip generators in the A428 corridor (west of the M11), including Cambourne and Bourn;

serves key current/future trip attractors in Cambridge – Cambridge City Centre and other employment sites;

intercepts trips from new developments from the outset; and

provides additional capacity for at least 500 passengers per morning peak hour.

attracts a mode share equivalent to 100% of growth in trips due to development and background growth, which may require:

- a peak service frequency of no less than six buses per hour (assumes standing);

- quality of waiting and in-vehicle environments comparable to the Busway;

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- peak journey times no more than the equivalent journey by car (and preferably less); and

- end to end journey time reliability better than the car alternative (as yet undefined).

results in no growth in delays on the A428 corridor for highway trips.

3.8. To achieve these planning objectives, in particular no additional delays/queuing on Madingley Rise, the solution(s) must encourage some existing car journeys to change mode; and attract a high share of new journeys (both from new developments and underlying growth). Additionally, options could seek to:

reduce demand for travel to/from Cambridge; and

‘re-time’ some car trips away from the peak periods.

3.9. Consideration was also given t options which would result in re-routing of some car trips onto alternative corridors. However, this approach is seen as, at best, inconsistent with broader strategy and may have limited results, given that there are few alternatives for A428/M11 traffic.

Geographic area of interest

3.10. This study considers the A428 / Madingley Road corridor between St Neots and Cambridge City Centre (see Figure3-1), a corridor which is expected to be subject to considerable growth in jobs and housing during the Local Plan periods. These major new development sites will be located around the Cambourne area, and they will need efficient connections to key destination sites (i.e. city centre, Addenbrookes Hospital, Cambridge Rail Station and the Cambridge Science Park).

3.11. At this stage, the priority is to identify solutions to the problems and challenges in the eastern half of the corridor between Caxton Gibbet and Cambridge. This is because:

the problems and challenges in this section are currently most acute;

growth in demand resulting from development in Cambourne and Bourn Airfield is expected to look first towards Cambridge rather than St Neots; and

it is the future problems and challenges which are expected to be the biggest threat to achievement of the Local Plan growth aspirations.

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Figure 3-1 A428 Western Corridor Study Area

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4. Option identification and sifting

Introduction

4.1. This chapter describes the process by which options were identified and assessed, and the outcomes of that process in terms of the long list and short list of options. The different stages of the process, and the number of options taken between different stages, are summarised in Figure 4-1 with the numbers in the arrows indicating the number of options at each stage.

Figure 4-1 Option process flowchart

Element identification process

4.2. Elements were identified by seeking to establish what types of interventions could:

fully or partially overcome the current and future problems and challenges identified (see Chapter 3) – the ‘bottom up’ context; or

support the wider policy aspirations of Cambridgeshire County Council, Cambridge and South Cambridgeshire District Councils and other stakeholders as established through the planning objectives – the ‘top down’ context.

4.3. The intention of the option identification process was to establish a broad range of alternatives which could support one or both of these contexts. The optioneering was informed by an understanding of constraints (such as environmental designations) and initial assessments of engineering feasibility. In practice, the element identification process for some elements was iterative as alignments and other features were altered as a result of further feasibility assessment.

4.4. Elements were identified by taking a holistic view across the corridor, looking through both top-down (what infrastructure can be provided to support growth) and bottom-up (what growth is forecast to take place that will require infrastructure to support it) approaches. Figure 4-1 highlights the key elements of the option generation process with the numbers in the arrows indicating the number of options at each stage.

4.5. The majority of options were identified during a workshop attended by the Atkins team and then presented to officers from Cambridgeshire County Council at a workshop, where a number of additional options were passed to Atkins for consideration by the client.

Brainstorm and Option

Generation34

Initial High Level Option

Sifting Process9 Workshop

12

Option Assessment

4Recommended

Options

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Long list of options identified

4.6. A total of 21 individual elements were identified including offline busways, online bus priority enhancements, Park & Ride, and traditional bus services. For all of these options, there were numerous potential variants relating to infrastructure alignments and locations; and service frequency and routing. At this stage, these were noted but not examined individually.

4.7. Most of the options identified could, at least to a degree, overcome the problems and challenges and/or support the planning objectives. However, in practice most would be delivered in conjunction with others as part of a package set of measures.

4.8. The 21 elements identified are listed in Table 4-1.

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Table 4-1 Long list of elements identified, and main variants

No. Brief description Variants

1 Offline busway, connecting Cambourne and Bourn Airfield before routing along the disused Bedford to Cambridge Rail Line to Trumpington.

Segregated or non-segregated alignment through Cambourne/ Bourn Airfield.

Services continue to city centre or Science Park.

2 Offline busway, connecting Cambourne and Bourn Airfield before routing south of Hardwick to M11 J12. Online services can run to Trumpington.

Segregated or non-segregated alignment through Cambourne/ Bourn Airfield.

Alignment further north to also serve Bar Hill.

3 Offline busway, connecting Cambourne and Bourn Airfield before routing south of Hardwick and Coton, crossing the M11 to connect to the existing Madingley Road Park & Ride Site.

Segregated or non-segregated alignment through Cambourne/ Bourn Airfield.

Route across M11 to A603 or join A603 west of M11 (north of Barton).

4 Offline busway, connecting Cambourne and Bourn Airfield before routing north to join the existing CGB at Histon.

Segregated or non-segregated alignment through Cambourne/ Bourn Airfield.

5 Offline busway, connecting Cambourne and Bourn Airfield before joining either the A428 or St Neots Road through to A428/A1303

Segregated or non-segregated alignment through Cambourne/ Bourn Airfield.

Run via A428 or St Neots Road as far as Madingley Mulch roundabout.

6 A bus bypass of Madingley Rise through a combination of on-road routing and bus gates. Optional offline route.

Alternative new link from Madingley Mulch roundabout to Cambridge road parallel and south of A428

Extra lane on A428 eb off-slip and bridge over A428 linking into Cambridge Road, avoiding MM r’bout.

7 A new Park & Ride site located adjacent to the A428 / A1303 junction

North of A428 junction (buses could run via bridge link in option 6).

East of Madingley Mulch roundabout (north of A1303).

East of Madingley Mulch(south of A1303).

8 A nearside inbound bus lane along Madingley Rise. Possible straightening of some sections.

Extend bus lane over M11 on new bridge (and straight into existing Madingley P&R).

Central tidal bus lane on Madingley Rise instead of inbound.

9 An offline busway to the south of Madingley Rise, joining at the A1303 / Cambridge Road junction.

Continue link across A1303 into existing P&R site on new bridge (as option 8)

10 A new highway link from the A428 / A1303 junction to M11 J12.

Also expand Trumpington P&R.

Close M11 Junction 13.

11 A nearside inbound bus lane along Madingley Road. Central tidal bus lane (outbound in evening)

12 Bus priority signalisation of the A428 / A1303 roundabout

13 Improvements on the western approach to the A428 / A1198 junction to provide bus priority

Provide dedicated straight on bus priority lane.

Grade separated junction

14 A higher frequency service between Cambourne and Cambridge.

Choice of destination (city centre or run to Science Park.)

Stopping/fast from Bourn Airfield.

15 An express service between St Neots and Cambridge.

16 A stopping service between St Neots and Cambridge Also stop Hardwick

17 A nearside eastbound bus lane along the A428 between Barford Road (St Neots) and the A428 / A1198 junction

Central tidal bus lane

A shorter bus lane starting near Caxton Gibbet junction eastbound queue (i.e. Eltisley).

18 A new Park & Ride site To the east of St Neots. Locate P&R at Eltisley (back of queue)

19 A new Park & Ride site located adjacent to the A428 / A1198 junction

3 potential locations

20 A new Park & Ride site located adjacent to Barton Road north of M11 Junction 12.

Potential location to east of M11.

21 A bus lane along Barton Road from M11 J12 to the A1134 (Fen Causeway).

Eastbound bus lane from A603 / Coton Road / Grantchester Road roundabout

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Option packaging process

4.9. As it was clear that most options would be more effective if delivered in combination with others, the options were packaged together prior to sifting. However, due to the potentially large number, it was impractical to test all combinations of options. An approach was therefore adopted that would develop packages of options around what were considered to be the core options (generally the larger options, or those which characterised the wider packages). These were Options 1-5, Option 7 and Option 18.

4.10. Packages were then derived around these core options, adding additional non-core elements in different combinations. The matrix shown in Figure 4-2 was used to identify where options were most compatible.

Figure 4-2 Option compatibility matrix

4.11. It is worth noting that the approach was designed to ensure each element was tested at least once, and that the final packages taken forward for assessment may differ from those identified at this stage. This process generated a total of 34 different packages to be assessed.

Initial option sifting process

4.12. The purpose of the initial sifting process was to narrow down the 34 packages to a smaller number which could be developed further and assessed in more detail. The packages were assessed using a framework consistent with the DfT’s ‘five cases’ model which has been developed to appraise transport business cases on the basis of HM Treasury’s Green Book appraisal. Each package was assessed in terms of:

the Strategic Case: the degree to which they were supportive of those planning objectives relating to the type and scale of intervention;

the Economic Case: the degree to which they were supportive of those planning objectives relating to the impact on ability to intercept trips and journey time reliability; environmental impacts; greenhouse gas emissions, social and distributional impacts;

the Financial case: the cost of the option;

the Commercial case: commercial viability of the option; and

Option no. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

Required/strongly synergistic

Can work as stand-alone

Optional

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the Management case: engineering feasibility, , stakeholder and public acceptability.

4.13. Each option was scored against each criterion using a Red/Amber/Green rating based on previously-determined definitions of what constituted each score for each criterion. Scoring was undertaken based on the team’s understanding of the corridor drawn from the SWOT analysis and professional judgement. Sense checking followed to ensure spurious results did not emerge, and the sifting table and results were then verified with senior members of the team not involved in the initial scoring. At this stage of the assessment, service frequency and quality was not used as a differentiator between options, since these factors could be tailored to best suit each individual package as required, therefore were not seen to be key factors for option differentiation.

4.14. The full assessment table for the initial sift can be found in Appendix B.3., page.44.

4.15. Based on the initial sift, the eight best-performing packages were selected and discussed at a workshop with CCC. During the workshop, three further options (8 to 11) were identified as being worthy of further investigation. Full descriptions of all eleven packages can be found in Appendix B.4 (page 45), and package maps can be found in B.1 (page 27).

Table 4-2 Preferred packages following initial option sift

Package Elements New no.

1.4 Busway from C/BA (southern route) + services

Caxton Gibbet Park & Ride

Madingley Road bus lane

Option 1

2.4 Busway from C/BA (southern central route) + services

Caxton Gibbet Park & Ride

Madingley Road bus lane

Option 2

3.4 Busway from C/BA (northern central route) + services

Caxton Gibbet Park & Ride

Madingley Road bus lane

Madingley Rise offline bus link [N.B. Not included in next stage]

Option 3

4.4 Busway from C/BA via existing CGB + services

Caxton Gibbet Park & Ride

Madingley Road bus lane

Option 4

5.2 Madingley Mulch Park & Ride + services

Madingley Rise bus lane

Madingley Road bus lane

Signalise Madingley Mulch roundabout

Option 5

6.2 St Neots Park & Ride + services

Madingley Rise bus lane

Madingley Road bus lane

Caxton Gibbet junction improvement

A428 bus lane

Signalise Madingley Mulch roundabout

Option 6

7a.2 Bus C/BA – Camb via A428 + services

Madingley Rise bus lane

Madingley Road bus lane

Signalise Madingley Mulch roundabout

Option 7

7b.2 Bus C/BA – Camb via St Neots Road + services

Madingley Rise bus lane

Madingley Road bus lane

Signalise Madingley Mulch roundabout

Option 8

New 1 Busway from C/BA (northern central route) + services

Caxton Gibbet Park & Ride

Madingley Rise southern bus bypass to Grange Road

Option 9

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Package Elements New no.

New 2 Busway from C/BA (northern central route) + services

Caxton Gibbet Park & Ride

Madingley Rise northern bus bypass to existing Madingley Road P&R Site

Option 10

New 3 Madingley Rise southern bus bypass to Grange Road

Madingley Mulch Park & Ride and + services

Option 11

Second assessment process

4.16. A more detailed assessment of each of the 11 options was undertaken to give greater quantification as to the potential benefits of each. This assessment combined elements of engineering feasibility and costs with transport related market benefits and potential market capture for each of the options. The aim of the further assessment was to determine a shortlist of options to propose for further detailed analysis within Phase 2 of this study.

4.17. During the assessment the options were defined and optimised further. For example, alignments were refined to avoid SSI sites, or utilise existing infrastructure (such as bridges over the M11) where possible.

Overview – completing the Appraisal Summary Table

4.18. The approach to option assessment was based on addressing three high level criteria, deliverability, strategic rationale, and benefits / impacts. For each option the team assessed:

Deliverability:

- Engineering feasibility – including flexibility of option, implementation timetable;

- Stakeholder acceptability;

- Environment impacts – including land take, green house gas emissions;

- Cost and affordability;

- Bus service commercial viability; and

- Key uncertainties.

Benefits / impacts:

- Social and distributional impacts

- Journeys in scope – intercepts all passenger transport trips in scope including non-car available;

- Journey time savings over car – offers peak journey times and journey time reliability that is equivalent to car based journey, and are preferable better than the equivalent car based journey; and

- Mode share.

Strategic Rationale:

- Provides congestion free PT serving the corridor – Cambourne and Bourn; and

- Serves key current / future trip attractors in Cambridge – including Cambridge City Centre, Addenbrooke’s Hospital, and the Science Park.

4.19. These criteria were assessed in detail in an Appraisal Summary Table (AST), using both a quantitative and qualitative process. The methodology used to assess the key criteria is described in more detail in the following sections.

Deliverability

Engineering feasibility and costs

4.20. To determine the engineering feasibility, the team used a process based on professional experience, by considering the number of junctions, river crossings, overhead power cables,

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amount of available land as well as any other constraints. In addition to this the ‘buildablity’ of each option was considered ensuring construction would be possible.

4.21. Costs for each route were estimated based on professional experience and by examining the cost per kilometre of previous similar schemes completed locally and nationally. The timescales and implementation timetable were estimated based on the use of concurrent construction methods (phased construction), and varied depending on the extent and complexity of the scheme.

4.22. During the development of the scheme options, and in order to reduce both the risk to delivery and the estimated costs, a review of features along each of the routes, such items as river crossings, listed buildings, sites of special interest, was conducted. Revised alignments and evidence based consideration was utilised to reduce the likely financial adjustment required to estimate the cost of the scheme, such as optimism bias, along with the risk associated with the delivery of the project.

4.23. The land take for each option was also considered, and assessed based on the extent and route of the expected corridor, assuming all land required is not currently owned by CCC. Similarly, the scale of impact was assessed based on land take, impact on the local population, the environment and an estimate of delays incurred during construction.

4.24. A summary of the assessment is shown in Table 4-3, and the full details are documented in Appendix C.1.

Table 4-3 Engineering cost and timescale summary

Option Cost estimate (millions) Total land take (m2) Build timescale (months)

Option 1 £91 341,000 24

Option 2 £35 254,000 14

Option 3 £36 237,000 21

Option 4 £65 284,000 23

Option 5 £22 160,000 16

Option 6 £39 200,000 24

Option 7 £48 40,000 13

Option 8 £30 40,000 15

Option 9 £82 282,000 22

Option 10 £82 296,000 25

Option 11 £66 230,000 22

Option 12 £22 50,000 15

4.25. It was identified that there was potential to reduce the cost, land take and timescale for Option 10 if the option was modified to bring the offline busway back on-line to the A1303 to the West of the M11, thus reducing the need for a new bridge. It is estimated that this would reduce the costs by up to £45million, while having a relatively low impact on the benefits for the public transport system.

Benefits / impacts

Prospective public transport demand

4.26. Each option has the ability to serve different markets within the A428 corridor, providing connections between different key origins and destinations. The options were analysed individually to determine which movements each option had the potential to serve, either through direct public transport connection, or via a Park & Ride site. This matrix of movements formed the basis for analysis of the total demand that each option could potentially serve as well as the mode shares expected for each option.

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4.27. The data used for this analysis was taken from the Cambridge Sub Regional Model (CSRM), utilising a model run for a forecast year of 2031 which included appropriate South Cambridgeshire and Cambridge City Local Plan housing allocations, the A14 Cambridge to Huntingdon Scheme (as presented at the Public Consultation held in Autumn 2013) as well as other notable large developments such as Cambridge North West, Darwin Green 2, Bourn Airfield & Cambourne West and development to the east of St Neots.

4.28. The model forecasts that there is likely to be severe congestion on the M11 to the west of Cambridge by 2031, caused by a number of different factors. Due in part to this, there is a high degree of internalisation between the Cambourne and Bourn Airfield developments which comprise of 4,500 jobs, with housing take-up at Bourn Airfield constrained by inability to access employment. Housing take-up is mostly by employed adults, with high car ownership levels and there is limited take-up by unemployed or retired households.

Demand in scope

4.29. Analysis of the data obtained from the CSRM enabled an estimation of the total person trip demand in the corridor between a number of key origin and destination sectors (see Appendix C.2.). By applying the matrix of movements served by each option, it was possible to estimate the total demand that each of the option has the potential to serve.

4.30. There is a range of demand that has the potential to be served by each of the options (see Appendix C.2.). However, it should be noted that the quality of service for each of the movements has not been taken into account at this stage, which therefore means that not all of this demand may be served well by each option.

Mode share

4.31. Analysis of the CSRM data was also undertaken to establish the forecast mode share for 2031 for the movements served by each option, to determine an estimation of potential mode share that each option could seek to achieve. This analysis assumes that these measures would not induce any mode shift towards public transport, and therefore the figures presented here are likely to form a worst-case in terms of forecast mode share for each package. This is based upon past experience with schemes such as the Cambridgeshire Guided Busway, where high quality public transport schemes have been shown to abstract trips away from cars.

4.32. By analysing the movement-by-movement mode share for public transport and Park & Ride trips, in combination with the movements forecast to be served by each option, it was possible to estimate the mode share that could be expected for each option. These figures can be seen in Appendix C.2.

4.33. It is noted that the forecast mode share for the evening peak period is lower than that for the morning peak period, however it is anticipated that for a high quality public transport scheme such as this, the mode shares are likely to remain consistent across the day as mode choice is likely to be influenced by the morning peak journey (when congestion is worse) with evening peak mode share therefore being roughly the transpose of the morning peak mode share.

Journey time savings

4.34. High level assessment of the potential journey times associated with each option was undertaken to determine the potential movements that could benefit from a journey time saving as a result of each option.

4.35. A 2031 highway journey time level was derived by taking observed data from TrafficMaster for 2011, and modifying this by the change in journey speed as forecast from the CSRM between 2011 and 2031. A spreadsheet model was then developed to forecast the journey times that could be anticipated for each of the options, but making assumptions for:

average time waiting for a bus;

average bus dwell time per stop;

average interchange time at a Park & Ride site (including parking, paying, waiting and boarding);

average bus speed in an on-road bus lane; and

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average bus speed on an off-road dedicated bus link or guideway.

4.36. By analysing the length of each type of measure proposed within each option and accounting for the number of interchanges and stops for each origin to destination pair served by each option, it was possible to estimate the end to end journey time provided by the option. For movements that included a Park and Ride interchange, the drive time taken to the Park and Ride site was the highway journey time for that section of the journey. Similarly, if a bus was to run on-road with no segregation, the journey time used was also that equivalent to the highway network at that point. This methodology also enables uni-directional bus lanes to be captured, by only applying the improved speed to a single direction of movements.

4.37. Combining all of these factors enabled an estimation of the potential change in journey time when compared to the highway network. It would be possible to determine if a particular movement was either faster or slower if made using the option assessed, therefore enabling an understanding of which movements were liable to receive journey time benefits from that particular option when compared to forecast highway conditions.

4.38. By undertaking a movement-by-movement comparison of the journey times via the proposed options or the highway network, it was possible to determine which movements would receive a journey time benefit from each option.

Demand ‘receiving benefits’

4.39. For the purposes of this analysis, it was assumed that journeys would be no change of mode to public transport unless the public transport journey was quicker than the current mode, but that there would be a mode change (in-line with the mode share values discussed above) if a journey time saving could be achieved. By utilising the movement-by-movement journey time savings in combination with the demand levels for each movement, it was possible to forecast the level of demand that may receive a benefit from each option as well as a demand-weighted average journey time saving per person for each option. These calculations can be seen in Appendix C.2.

4.40. Table 4-4 below provides a summary of the modelling results. Further details can be found in Appendix C.2.

Table 4-4 Modelling results summary

Option Total Person Trips in Scope by 2031(AM 3 hours plus PM 3 hours)

Average Journey Time Saving per Person Over Car in 2031

Indicative Mode Share in 2031 AM Peak

1 8,200 Between 4 and 5 minutes 28% or greater

2 9,900 Between 2 and 5 minutes 25% or greater

3 13,100 Between 2 and 4 minutes 23% or greater

4 8,800 Up to 1 minute 24% or greater

5 2,700 Between 3 and 10 minutes 46% or greater

6 5,400 Between 4 and 9 minutes 30% or greater

7 4,700 Up to 7 minutes 40% or greater

8 8,000 Up to 4 minutes 32% or greater

9 13,100 Between 2 and 4 minutes 23% or greater

10 6,800 Between 4 and 7 minutes 34% or greater

11 5,100 Between 3 and 8 minutes 44% or greater

Strategic rationale

4.41. A qualitative assessment of the options was undertaken to determine which options best served key trip attractors and locations of high demand. This assessment was based on professional judgement, and the logic chain and approach used can be seen in Figure 5-3

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Figure 5-3 Demand-based option assessment process

4.42. Using this approach, the sequence of assessment was as follows:

1: Does the option serve the City Centre well?

The City Centre was identified as a key destination, and hence the success of any option hinged on serving this destination well. Options 1, 2 and 4 were deemed not to serve the centre well, as they link into existing busways focused on other key destinations. The remaining options had the potential to serve the City Centre well, with some of them hinging on the success of an inbound-only bus lane on Madingley Road.

2: Does the option serve the Science Park well?

All options were considered to serve the Science Park equally.

3: Are St Neots to Caxton Gibbet journeys a key priority for this study?

The main focus of the study has been on the area to the East of Caxton Gibbet, where the new developments are planned. If improving the corridor from St Neots is a priority, then Option 6 would be the best at delivering this outcome. It is worth noting that Option 6 can be combined with some of the other options, and it may be appropriate to consider it as a later phase in any proposed programme of improvements to the corridor.

4: Does the option serve North West Cambridge development?

All options were considered to serve the North West Cambridge development equally.

5: Does the option pick up demand between Cambourne / Bourn and Cambridge?

Consideration was given to whether options would intercept demand directly at the main developments (therefore being accessible to non car owners) or whether they required users to perform some of the journey by car. Options 3, 8, 9 and 10 have the ability to cater for passengers joining the service at Bourn and Cambourne, while 5 and 11 rely on P&R.

6: Does the option cater for high demand?

The final consideration was whether the options had the potential to cater for high demand, based upon the movements that each would serve.

4.43. This approach was used to determine which options would perform best serving the key trip attractors. The options which performed well were examined to determine whether they also performed well against the remaining assessment criteria (such as feasibility, costs environmental constraints etc) identified above.

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4.44. In undertaking the assessment above, a further option was identified, that being a combination of options 7 and 11. Whilst no modelling work on this option has been undertaken, it is considered to be sensible to take this option forward to the next stage rather than options 7 or 11 individually.

4.45. The options were presented to the client at a workshop attended by officers from Cambridgeshire County Council. The assessment process was described at the workshop, including the rationale used to assess whether the options served key trip attractors, and the recommended options were discussed. .

Recommended options

4.46. At the client workshop, it was agreed that the following options should be taken forward to Phase 2 of the study:

Option 3 (Park & Ride at Caxton Gibbett, a segregated bus route via Cambourne and Bourn Airfield re-joining Madingley Rise just west of the M11, and an eastbound nearside bus lane on Madingley Road);

Option 5 (Park & Ride at Madingley Mulch, signalisation of Madingley Mulch roundabout, a nearside eastbound bus lane on Madingley Rise and Madingley Road);

either Option 7 (a segregated bus route through Cambourne and Bourn Airfield, with services then running via a new junction with the A428 to Madingley Mulch roundabout, signalisation of Madingley Mulch roundabout, a nearside eastbound bus lane on Madingley Rise and Madingley Road, potential intermediate Park & Ride at Bourn Airfield); or Option 8 (as Option 7, but alternatively running via St Neots Road rather than tha A428);

Option 10 (a segregated bus route via Cambourne and Bourn Airfield re-joining Madingley Rise just west of the M11 having run to the north of Madingley Rise from Madingley Mulch (note this is a modification of the previous Option 10 which assumed a new M11 over bridge), nearside eastbound bus lane on Madingley Road); and

either Option 7 or Option 8 plus Option 11 (Park & Ride at Madingley Mulch, segregated offline bus route south of Madingley Rise and Madingley Road).

4.47. These options, at a high level:

Meet the strategic rationale for the intervention;

Are deliverable in engineering terms, could be affordable, and do not have any obvious ‘show stoppers’ that would render them undeliverable on environmental grounds or in terms of stakeholder acceptability; and

Could deliver significant benefits / impacts in terms of capturing demand, mode share / shift, and journey times.

4.48. As noted before, this is a high level assessment, and these factors will need to be appraised in detail in Phase 2 of the study using DfT’s ‘five cases’ approach.

Phase 2

4.49. The proposal for Phase 2 of the project indicated that 4 options will be taken forward for detailed testing. Therefore a critical review of the above proposals from Phase 1 was undertaken.

4.50. Analysis of the benefits of these options and consideration of feedback received from Cambridgeshire County Council has indicated that Option 3 should not be taken forwards for further detailed analysis. There are several reasons why this option is considered to be the least suitable for further assessment, which are detailed below:

Questions have been raised as to how justifiable a new offline route parallel to the current A428 would be in terms of bypassing congestion. While it is acknowledged that Option 10 also has a similar dedicated route and therefore has similar PT service potential, the Option 3 P&R location makes this option less effective due to the bus travel times between Caxton Gibbet and the A428/A1303 junction being greater than the equivalent car journey via the A428. Therefore while the options are similar in the majority of aspects, the more optimal P&R service potential for Option 10 means that there is limited value in also testing Option 3;

Madingley Road / A428 Corridor Study Options Appraisal Report

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Option 3 does not include (or allow for) a Park & Ride site located adjacent to the A428/A1303 junction. Work undertaken during Phase 1 clearly showed that trips from further afield would benefit from being able to drive along the entire A428 dual carriageway in preference to switching to public transport due to the bus travel times being greater between Caxton Gibbet and the A428/A1303 junction than the equivalent journey by car. Therefore, the most effective Park & Ride site location is not likely to be that at either Caxton Gibbet or Bourn Airfield; and

Option 3 would only have an inbound bus lane from the A1303/Cambridge Road junction to the M11, while Option 10 would be able to bypass a much greater length of Madingley Rise in both directions before connecting to the existing bus priority provision.

4.51. When comparing the two potential offline options between Cambourne and the M11, the comments above all point towards Option 10 being the most likely scheme to provide benefits in this corridor. Atkins considers it important that at least one option which includes a dedicated offline link should be tested during Phase 2 to gain an accurate picture of all potential options available.

4.52. Option 7 is also not considered to be taken forwards, since this option would rely on a new junction with the A428 dual carriageway to be constructed north of Bourn Airfield. Since this is unlikely to be completed as part of the development itself and therefore cannot be relied upon as committed infrastructure, the cost of such works (estimated to be around £20m for the junction alone) would make this option un-economic. Therefore, option 8 will be considered for on-road services between Bourn Airfield and the A428/A1303 junction.

Final Recommendation

4.53. Based upon this analysis, it is recommended that the following options are therefore taken forwards for detailed analysis in Phase 2.

Scheme A (formerly Option 5) (Park & Ride at Madingley Mulch, signalisation of Madingley Mulch roundabout, a nearside eastbound bus lane on Madingley Rise and Madingley Road);

Scheme B (formerly Option 8) (a segregated bus route through Cambourne and Bourn Airfield, with services then running via St Neots Road to Madingley Mulch roundabout, signalisation of Madingley Mulch roundabout, a nearside eastbound bus lane on Madingley Rise and Madingley Road, potential intermediate Park & Ride at Bourn Airfield);

Scheme C (formerly Option 10) (a segregated bus route via Cambourne and Bourn Airfield re-joining Madingley Rise just west of the M11 having run to the north of Madingley Rise from a Park & Ride Site at Madingley Mulch , nearside eastbound bus lane on Madingley Road); and

Scheme D (formerly Option 8 plus Option 11) (Park & Ride at Madingley Mulch, segregated offline bus route south of Madingley Rise and Madingley Road – this would not include a potential intermediate P&R located at Bourn Airfield due to the proximity with the new P&R located at Madingley Mulch).

4.54. Figures depicting these proposed schemes can be seen below. It should be noted that further refinement of all options will take place during the more detailed assessments to be undertaken during Phase 2 of this study. This refinement will seek to establish which elements from each scheme perform well, and may result in the emergence of other schemes which may be a combination of Schemes A-D.

Madingley Road / A428 Corridor Study Options Appraisal Report

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Figure 4-4 Scheme A

Figure 4-5 Scheme B

Madingley Road / A428 Corridor Study Options Appraisal Report

Atkins Options Appraisal Report | Version 1.0 | 20 June 2014 | 5131840

Figure 4-6 Scheme C

Figure 4-7 Scheme D

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