Response to SPD for land north of Cherry Hinton

The Supplementary Planning Document (SPD) for development of land north of Cherry Hinton has significant transport implications for Cambridge and South Cambridgeshire. It could exacerbate congestion on already-constrained routes between Cambridge, Cherry Hinton, Teversham, Fulbourn, the Wilbrahams, and other villages to the east of Cambridge. On the other hand it could be the catalyst for greatly improving sustainable transport options in this area.

Our response pertains to the section of the SPD on Movement and covers:

  • Impact the development will have on the local road network, and the modal shift required to offset that impact.
  • Inadequacy of the proposed mitigations.
  • Role of a railway station in stimulating modal shift.
  • Opportunity to improve the urban environment of Cherry Hinton by re-routing through traffic away from the village.
  • Requirement for walking and cycle routes to be available from when residents first move in.

References

Impact

The addition of 1,200 homes (around 3,000 people) to Cherry Hinton village will give rise to a significant increase in trips on connecting roads – even if an extraordinarily high percentage of those trips is by sustainable transport modes (walking, cycling and bus).

New developments should be aiming for a zero net impact on road traffic. This is illustrated in Figure 1. The inevitable increase in car trips generated by the new community must be offset in the existing community by a modal shift from car to sustainable alternatives.

Take a community that generates 10,000 trips daily, of which 20% are by sustainable modes. Adding another 2,500 trips with no net increase in car trips requires new and existing communities to achieve a 36% sustainable mode share. This is a very rough approximation of the likely impact of the proposed development, and illustrates how big the challenge is.

Bar chart showing modal shift

Figure 1: Imagine a community generates 10,000 daily trips, of which 20% are by sustainable transport modes. Adding another 2,500 trips with no net increase in car trips requires new and existing communities to achieve a 36% sustainable mode share.

Mitigation

The transport proposal for the development proposes two ways to mitigate the increase in trips:

  1. An increase in local bus services.
  2. Provision of new or upgraded segregated cycle routes into Cambridge (‘the Tins’ path and potentially via Coldham’s Common to the Chisholm Trail).

Our assessment is that it is most unlikely – and almost certainly unprecedented – that the required large modal shift may be achieved simply by running more buses and upgrading cycle paths.

Bus services

Increasing bus services is not in the gift of the landowners, developer or planning authorities, as the draft SPD admits: “Any strategy for public transport must be led by the County Council, in partnership with the local authorities, bus companies and developers. The proposed public transport strategy for the site will build upon the existing network.” Some Section 106 money might be set aside to ‘pump prime’ services, but this rarely achieves a high bus patronage:

  • There is rarely enough subsidy money to run a high frequency service for the hours that people need it (i.e. comparable to something like the Citi 1 service) from the time when people start moving into the development to completion (typically a number of years).
  • The bus operator is expected to cover a proportion of the operating costs, which makes the service loss-making at the outset. Operators will generally not risk making that investment because, if and when the route does become profitable, another operator could push them out by aggressive competition.

Furthermore the “existing network” uses roads (Cherry Hinton Rd and Hills Rd) that are already very congested at peak times, making bus services unreliable and relatively expensive to operate.

Altogether, this is not a recipe for a large modal shift to bus travel.

Cycle routes

A reasonably well-used cycle route already exists between Cherry Hinton and Cambridge city centre via ‘The Tins’ path. Adding a dedicated onward link into the new development is essential, but is unlikely to attract a significantly higher percentage of cycle journeys than is already seen from Cherry Hinton.

Diverting traffic away from the village end of Coldham’s Lane (see below) would make this road more conducive to cycling, and encourage more people to cycle for short trips, e.g. into the centre of Cherry Hinton.

Upgrades to cycle routes to destinations in Cambridge (city centre, station, Science and other business parks, etc.) would increase cycling modal share for commuting, leisure and other trips. However to make a large difference, enough to offset car trips generated by the new development, would require very large investment far beyond the development site to create new routes and links, and to remodel road junctions.

There seems to be an inconsistency in the interpretation of planning law: if the SPD cannot make reference to a new railway station, how can it refer to unplanned cycling infrastructure far beyond the development site? It is therefore unclear how this will be funded as a development condition or planning obligation.

Examples of improvements needed include:

  1. A protected cycle lane alongside Coldham’s Lane, at least as far as Nuttings Rd. This would enable cycle access to Barnwell Rd, home to a number of large employers and shops.
  2. Improved walking/cycling access to and around the roundabout at Barnwell Rd–Brooks Rd (see Figure 2). The roundabout could be remodelled to a Dutch design (an outer pedestrian & cycling ring, and a single lane for motor traffic). The narrow tunnel under the railway is a particularly challenging obstacle for improving access.
  3. Improved walking and cycling access around the Barnwell Rd–Newmarket Rd roundabout (see Figure 3).
  4. Improvements to the cycle links between Cambridge, Cherry Hinton and Fulbourn, including making crossing Perne Rd safer (See Figure 4), reducing conflict at the steep and narrow bridge over the railway, and improving the connection around Yarrow Rd. The Greater Cambridge Partnership Greenways project may provide some or all of the required investment.
Map showing reported collisions

Figure 2: Collision data 2005-16 at Coldham’s Lane–Barnwell Rd roundabout (dark purple = severe injury; light purple = slight injury) © Cyclestreets/OpenStreetMap

Map showing reported collisions

Figure 3: Collision data 2005-16 at Newmarket Rd–Barnwell Rd roundabout (dark purple = severe injury; light purple = slight injury) © Cyclestreets/OpenStreetMap

Map showing reported collisions

Figure 4: Collision data 2005-16 on Perne Rd where The Tins path from Cherry Hinton connects with Natal Rd (dark purple = severe injury; light purple = slight injury) © Cyclestreets/OpenStreetMap

Rail

Possibly the only way to achieve a large modal shift is to provide a rail station on the existing railway line, with a frequent service into Cambridge and from Newmarket and Bury St Edmunds.

We have proposed that a new station be built at the point where Fulbourn Old Drift used to cross the railway line (see Figure 2). The south side is readily accessible from Fulbourn and much of Cherry Hinton. With improvements to Fulbourn Old Drift on the north side of the railway line, the station would also be easily accessible from northern Cherry Hinton, the proposed new development and Teversham. We envisage that the station would provide only disabled parking, so as not to attract more motor traffic.

This new station would enable residents of Cherry Hinton, Fulbourn and Teversham wanting to access the wider rail network (Cambridge North, London, Stansted Airport, Norwich, Peterborough, Birmingham, etc) without driving to Cambridge station. Significantly, 203 new houses are planned for the redeveloped Ida Darwin Hospital site, adjacent to our proposed site for the station.

The station would also give workers at the local employment sites a practical alternative to driving into work at Peterhouse Technology Park (home to ARM), Capital Park, Fulbourn Hospital, Tesco, etc.

Map showing rail stations

Figure 5: Proposed location for a new railway station serving Cherry Hinton, Fulbourn and Teversham on the Newmarket line. Also showing: Cambridge and proposed Cambridge South stations. Map © OpenStreetMap.

Adding a station and providing a regular service would require reinstating a dual track between the Coldham’s Lane junction and Dullingham. This is planned as part of implementing East-West Rail.

We understand that the SPD cannot make explicit reference to a new railway station as none is yet planned (although the County Council Long Term Transport Strategy does make reference to “Consideration of new station(s) in the Cherry Hinton / Fulbourn area” (page 4-14). The local authorities need to address this lack of foresight urgently. If it is the case (as seems most likely to us) that the proposed development cannot be made sustainable without a railway station, then this must be stated in the SPD.

We recommend the local authorities, Greater Cambridge Partnership, the Combined Authority, East-West Rail and Network Rail work together with the landowners (outside of the planning system) to deliver a station before houses are occupied on this development.

Road

Two options are being proposed for the ‘spine road’ through the development. We understand that these options are proposed as the access route to the new development and not as a through route. However both options internally divide the new development and isolate it from the rest of Cherry Hinton. It would be a big mistake to create yet another ‘cul-de-sac’ development.

Unfortunately the Cambridge Local Plan provides misleading guidance on this (Policy 8/11):

Any proposed road must:

  1. be designed to give high priority to the needs of pedestrians and cyclists, including safety;
  2. restrict through-access for general motor traffic where possible;
  3. minimise additional car traffic in the surrounding area; and
  4. be acceptable to the Highway Authority in all other respects.

8.25 Roads providing a new vehicular through-route will not generally be supported, because they would be likely to attract car traffic from more major roads.

This policy does not take into account the possibility of creating a road as a bypass that enables a reduction or restriction of through traffic on existing residential roads.

Through road

We believe that two other options should be considered, both providing a new through route between Coldham’s Lane and Airport/Gazelle Way. The intention would be to displace through traffic, including many goods vehicles, away from north Cherry Hinton (the eastern end of Coldham’s Lane, Cherry Hinton High St, and Teversham Drift). This could transform the village, making it much more conducive to walking and cycling.

Both options would remove road barriers to permeability for people walking and cycling, which would ensure better integration of the new development.

Option C (Figure 6)

This option would be similar to Primary Street Option A in the Draft SPD, but would see the road designed for 40mph speeds – the same as Gazelle Way. As such, it should be buffered, visually and auditorily, from the new development with appropriate landscaping.

This would be relatively easy to achieve on the western section of the road, where it is adjacent to the airport and on the edge of the development. More challenging would be the eastern section of the road, where it divides the development. One option that could be considered is to build a wide green bridge over the road (see Figure 7). The additional construction cost would be partly or largely offset by having more land available for development, and the value of the land around the road being higher (since it would look out onto quiet green space rather than a busy road).

Option D (Figure 8)

This option has a road that runs entirely around the edge of the development and alongside the airport. This would connect with Airport Way at the junction with Cherry Hinton Rd from Teversham. This provides a less direct route between Coldham’s Lane and Gazelle Way, but is only slightly further if heading for the A1303 or A14.

Map showing Option C

Figure 6: Primary road option C, similar to option A, but designed to carry through traffic, and covered where it bisects the development. Orange arrows indicate main vehicle access points to development. Map © OpenStreetMap

Aerial view of Mile End Road

Figure 7: Example of a ‘green bridge’ over Mile End Road in East London. © Microsoft

Map showing Option D

Figure 8: Primary road option D, which follows the perimeter of the development. Orange arrows indicate main vehicle access points to development. Map © OpenStreetMap.

Internal roads

Other roads through the development should be primarily for walking and cycling, as in the Eddington development in North West Cambridge. Vehicle movements should be confined as far as possible to the outer edges of the development, to ensure that the public outdoor space is attractive and safe for people of all ages to move around, and for children to play. This goes slightly beyond the aspiration set out in the Cambridgeshire Quality Charter, “Primacy should be given to walking, cycling and community transport,” and Cambridge Local Plan (Policy 8/4):

To support walking and cycling, all development will be designed to:

  1. give priority for these modes over cars;
  2. ensure maximum convenience for these modes;
  3. be accessible to those with impaired mobility; and
  4. link with the surrounding walking and cycling network.

Further afield

Some of the most severe congestion experienced is at the roundabout at the end of Coldham’s Lane by Sainsbury’s. Better regulation of the traffic, perhaps with yellow boxes or part-time lights, might provide short-term relief for motor vehicles, but wouldn’t solve the problem or improve matters for people walking and cycling (see Figure 2). Investment should instead be focused on making sustainable transport options more convenient, safe and attractive (see example 2 under Cycle Routes above).

Data

Policy 8.25 of the Cambridge Local Plan requires a “suitable quantitative assessment of the likely effect of the new road will be essential.”

It is notable that the County Council collects no traffic data for Cherry Hinton Rd, Coldham’s Lane, Cherry Hinton High St, Teversham Drift, Gazelle Way or Airport Way. Nor is there any data on destinations for trips originating in Cherry Hinton – and not only commuting, which typically accounts for only about 25% of all trips.

This data is essential in order to assess the transport impact of this development, and how effective different mitigations may be.

Construction

Lessons must be learned from the Great Kneighton development in Trumpington: much of the housing is now occupied, and the secondary school is partially open. However, access through the development on foot or bike involves a constantly varying route over muddy roads, mixing with construction vehicles. By contrast, movement by car is easy, facilitated by huge multi-lane junctions with Long Road and Shelford Road that were opened before any residents moved in.

This is not conducive to encouraging new residents, especially with young children, to adopt a car-free or low-car lifestyle.

For this development, it is imperative that safe and convenient walking and cycling routes to local amenities and bus stops are open from the moment that people start moving in. They must remain open and safe to use throughout the construction period.

Conclusions

  1. Because of the need to achieve a high modal shift from driving to sustainable transport modes, we believe that the viability of the proposed new development is dependent on provision of a nearby railway station and regular rail service into Cambridge.
  2. To achieve the high modal shift to cycling and walking required to offset the increase in car trips would require large investment far from the development site. It is unclear how this will be funded.
  3. This development offers the opportunity to route traffic away from north Cherry Hinton, and thereby to greatly improve the urban environment for existing residents and visitors to the village. Two additional options should be considered: a perimeter road and a more direct link to Gazelle Way, with the part running through the development covered by a green bridge.
  4. The layout of the development should be one that prioritises walking, cycling and playing outside over convenience for motor vehicle owners.
  5. The construction schedule must prioritise delivery of walking and cycling routes before homes are occupied, and those routes must remain open during construction work.

With these additions to the SPD this development could radically transform the connectivity and quality of life in Cherry Hinton, Teversham and Fulbourn.

The local authorities must ensure that planning consent, conditions and obligations take full and realistic account of the scale of this development and the impact it will have on the area.

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