THEME 7 - DEVELOPMENT SITE LOCATION
Development site location refers to the selection of sites for new housing allocations or other new developments. This covers the type of decision that would generally be taken early in the Local Development Framework (LDF) process within the context of housing provision figures set by the Regional Spatial Strategy (RSS) or, in future, the single Regional Strategy (RS). Development site location is often a catalyst for transport interventions, helping to justify or making viable a new transport service. The selected development site should also be well integrated into the existing urban fabric, including local transport networks (existing and new).
The aim of good development site location in relation to sustainable travel should be to locate new housing where:
- The amount of travel by car (trip length and mode share) is likely to be low.
- Good accessibility is available, or can be developed, by sustainable modes to:
- employment and other main facilities in the main towns or immediate vicinities
- a rail station or other public transport interchange where good services are available to other (larger) centres within the sub-region
- community facilities within the development or the surrounding neighbourhood
- Opportunities exist to:
- promote the use of walking, cycling and public transport
- provide an attractive level of public transport service which does not depend on (additional) subsidy over the longer term
- utilise and support existing public transport services and community facilities in the locality
- incorporate services or facilities within the development which will improve accessibility by sustainable modes
- In certain locations, car-free or low car provision housing will be appropriate
1. To what extent does development site location affect travel?
Development site location, in terms of the relation to surrounding urban areas, facilities and also transport networks can have an important impact on the type of travel generated. This is particularly in terms of the length and mode of trips. Strategic development location, accessibility of key facilities, mix of uses, neighbourhood design and street layout are also closely related.
2. How should we assess alternative development site locations in order to encourage sustainable travel?
A systematic and transparent process is important, with appraisal of options against agreed criteria. Existing and future accessibility, particularly by public transport, walking and cycling, is critical. Linkages into surrounding transport networks can usually be improved alongside the new development. The potential for wider traffic demand management measures should also be considered.
“In support of its objective of creating mixed and sustainable communities the Government’s policy is to ensure that housing is developed in suitable locations which offer a range of community facilities and with good access to jobs, key services and infrastructure. This should be achieved by making effective use of land, existing infrastructure and available public and private investment. […] The priority for development should be previously developed land, in particular vacant and derelict sites and buildings”. (PPS3, para 36)
“Local Development Documents should set out a strategy for the planned location of new housing which contributes to the achievement of sustainable development [...] taking into account:
- the contribution to be made to cutting carbon emissions from focusing new development in locations with good public transport accessibility and/or by means other than the private car
- accessibility of proposed development to existing local community facilities, infrastructure and services, including public transport. The location of housing should facilitate the creation of communities of sufficient size and mix to justify the development of, and sustain, community facilities, infrastructure and services”. (PPS3, para 36)
Planning Checklist: Development Site Location
Practitioners working at the local level are advised to adopt a systematic process of identifying new sites for housing development, subject to availability of sites and other considerations, e.g. flood risk, design and conservation aspirations, as follows:
7.1. Identify and/or assess sites for housing development on the basis of existing accessibility by car and public transport to employment and other key facilities (alongside, but potentially before, other policy objectives). This will help ensure that existing transport investment and services are utilised and requirements for new investment are minimised. Deficiencies in accessibility are unlikely to be remedied by transport measures that can be introduced as part of smaller scale development.
7.2. Include the location and quality of existing bus routes and local facilities, as well as the opportunities presented by the development to bring about improvements in accessibility, as key criteria for final site selection. In particular:
- in larger towns: incorporate necessary network links in the layout of development to enable utilisation and enhancement of existing urban bus services. Larger extensions may justify a dedicated bus service along a radial corridor with priority measures
- in small towns: focus development on radial corridors in order to utilise and support inter-urban bus services that run along them. Again larger extensions may justify their own frequent bus service
7.3. Create attractive walking, cycling and public transport links with local facilities in the neighbourhoods surrounding the new development.
Evidence and Examples
The evidence given here is necessarily selective, but gives an introduction to the research on this topic. More details are found in the background technical report.
Research concerning transport energy consumption by households within Surrey illustrates the complexity of the relationship between development site location and travel. As expected, transport energy consumption by households falls as public transport accessibility improves. Moreover, transport energy consumption is generally lower for households located close to the town centre and higher for those located further away. However, households located in the 25-30 minute isochrone relative to the town centre are associated with the least energy consuming patterns. That is, they use 13% less energy for transport than the sample average in 1998. This may be because households located closer to the urban core are associated with long journey lengths due to the tendency to commute longer distances by rail (Hickman and Banister, 2007a).
These observations illustrate not only the potential impact of household location on sustainable travel but also the need to carefully examine underlying assumptions about accessibility (e.g. always better closer to urban core) using an evidence-based approach.
Research in Portland (Oregon) and Toronto metropolitan areas illustrate the relationship between total travel by car and the accessibility of households to jobs. The studies found that total household vehicular travel (in terms of vehicle miles/hours travelled) is primarily a function of regional accessibility between jobs and households. The studies conclude that the effects of local density and mix of uses are modest by comparison to regional accessibility, therefore dense, mixed use developments in the ‘middle of nowhere’ may offer only modest regional travel benefits (Kasturi et al, 1998; Pushkar et al, 2000). Again this highlights the importance of multi-variate analysis and policy implementation.
Further reading here
Longbridge, Birmingham - Development at Longbridge is well integrated into the existing urban fabric with new links to the public transport network.
Northstowe, South Cambridgeshire - Similarly, the planned Cambridge station redevelopment develops new routes into the existing station, including new linkages over the rail lines.
Didcot, Oxfordshire - In Oxfordshire, a study of potential ‘directions of growth’ for Didcot resulted in the decision to expand the town to the west rather than the north. Reasons included proximity to major employment areas and a nearby connection to the A34 to Oxford (thus reducing traffic on rural roads).