Planning for Sustainable Travel

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Accessibility refers to the ease of reaching destinations or activities . Places that are highly accessible can be reached by many people quickly, whereas inaccessible places can only be reached by a few people in the same amount of time. The focus for practitioners can be on improving accessibility rather than mobility, and in moving people rather than vehicles. There are urban and rural dimensions to accessibility planning.


Accessibility is conventionally perceived in physical travel terms, but electronic social interaction is becoming increasingly important. As yet there is little evidence of an aggregate substitution effect (with electronic travel replacing physical travel) – interaction tends to increase. But this may change over time as the ‘network society’ takes off (e.g. Castells, 1996; Hall and Pain, 2006; Choo et al, 2005).

Key facilities serve a wider catchment than the immediate neighbourhood in which they are situated. Examples include employment centres, shopping centres, hospitals, educational institutions, leisure centres and cultural attractions. The accessibility of key facilities is therefore of particular importance because they are major travel generators (for both employees and patrons) and wider access has strong additional social benefits. Lack of accessibility to key facilities tends to be a larger challenge in rural areas and areas of multiple deprivation. Accessibility to local facilities, such as neighbourhood shops and other day-to-day facilities is also important (see related mix of uses). When facilities are closed, accessibility levels can be difficult to maintain.

To pro-actively encourage sustainable travel, the aim should be to locate and manage key facilities so that they will:

Key Questions

1. To what extent does the accessibility of key (regional) facilities encourage sustainable travel?

Good accessibility by different modes widens catchment areas, hence has a strong social dimension. Careful development site selection and transport investment can have a large impact on distance travelled. Development located in areas of good public transport accessibility is associated with reduced car-based travel.

2. How can we measure the accessibility of key facilities?

Accessibility planning is a key tool to be used here. Travel time maps can be used to indicate accessibility to/from a given location(s) using contours (or isochrones) of equal travel time. Various mathematical approaches can be used to calculate travel time maps. The Department for Transport provides a set of national core accessibility indicators that detail levels of accessibility to key services. These include education, healthcare, employment and shopping facilities. Accession accessibility planning software (see useful tools) is being used by many local authorities in the UK to assess accessibility of key services by different groups across modes, particularly during the Local Transport Plan process, but could be more widely used in Local Development Frameworks.

Selective Policy Guidance ShowHide

“Local authorities should:

  • focus land uses which are major generators of traffic demand in city, town and district centres and near to major public transport interchanges. City, town and district centres should generally be preferred over out of centre interchanges. Out of town interchanges should not be a focus for land uses which are major generators of traffic demand
  • actively manage the pattern of urban growth and the location of major travel generating development to make the fullest use of public transport
  • take into account the potential for changing overall travel patterns, for instance by improving the sustainability of existing development through a fully coordinated approach of development plan allocations and transport improvements….

Local authorities should seek to make maximum use of the most accessible sites, such as those in town centres and others which are, or will be, close to major transport interchanges. These opportunities may be scarce. They should be pro-active in promoting intensive development in these areas and on such sites. Local authorities should review their development plan allocations and should allocate or reallocate sites which are (or will be) highly accessible by public transport for travel intensive uses.” (PPG13, paras 20 and 21)

“Through regional spatial strategies and local development documents (local planning authorities) should:

  • develop a hierarchy and network of centres
  • assess the need for further main town centre uses* and ensure there is the capacity to accommodate them
  • focus development in, and plan for the expansion of, existing centres as appropriate…”

*Main town centre uses refer to facilities for retail, leisure, entertainment and the more intensive sport and recreation uses, offices and arts, culture and tourism. (PPS6, para 1.6)

“Accessibility strategies were covered extensively in the last LTP Guidance in 2004, and in related guidance specific to accessibility planning. These documents remain relevant and accessibility planning will continue to be a key element of local transport planning and delivery. The DfT is currently undertaking a long-term process and impact evaluation of accessibility planning. An initial report is expected in mid-2009.” (LTP3 draft guidance, para 54).

Guidance on accessibility planning in Local Transport Plans is here

More here

Planning Checklist: Accessibility of Key Facilities

Practitioners are advised:

6.1. As far as is practicable, to locate key facilities within town, suburban and rural centres which relate to the catchment areas of the activities concerned, in order to:

  • minimise trip distances and travel time to individual facilities
  • create opportunities for trip purposes to be combined in a journey to a single destination (i.e. a centre with a mix of uses)
  • provide a high level of public transport service in terms of frequency and speed (as a consequence of the concentration of travel flows)
  • help develop a parking management programme (public and private) consistent with a concentration of traffic demand in high density areas

6.2. Planning policy guidance requires the identification of a hierarchy of centres. Selection and assessment criteria for centres at the same level of hierarchy should include:

  • relative accessibility by public transport from the residential population they are intended to serve and from the area where their workforce will be drawn
  • accessibility by car compared with other modes

6.3. If the full requirement for major employment and key facilities cannot be met within established centres, consider other locations on the public transport network which offer, or can be improved to offer, similar levels of accessibility from the relevant catchment area.

6.4. Where key facilities (and/or major employment sites) must be developed outside established centres, include a mixed use element to facilitate multi-purpose trips and traffic demand management measures and controlled parking on site to complement parking restrictions in the vicinity.

6.5. Where existing centres are redeveloped, seek to enhance accessibility for buses, other public transport and walking and cycling. Attempt to mitigate the transport consequences when facilities are closed, e.g. hospitals.

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.

Hägerstrand (1970) initially developed the notion of time-space geography, with the ‘time-space path’ illustrating the movement of an individual within the constraints of space and time. This work has been influential in transport planning, particularly in the development of accessibility planning as a discipline.

Accession software can be used to assess accessibility of key services by different groups across modes using core accessibility data provided by the Department for Transport. The DfT’s public transport accessibility indicators detail public transport accessibility to key services, including education, healthcare, employment and shopping.

Farthing et al (1997) explore the diversity of services and facilities; with proximity and diversity reducing distance travelled. Some researchers have found that accessibility to key regional facilities has a greater impact on the frequency and length of trips by households than density or land use mix in their immediate neighbourhood, although other research has shown these factors to be influential (Ewing, 1995; Kasturi et al, 1998; Pushkar et al, 2000).

Local accessibility, defined as commercial employment within a zone, and regional accessibility, defined as access to regional centres, have been found to influence retail trips, with shorter distances where accessibility is high (Handy, 1993). In other words, shopping trips are shorter at locations with high local or regional accessibility. Total vehicle miles travelled (VMT) were lower at locations of higher regional accessibility (Cervero and Kockelman, 1997).

Further reading here

Summary Guide Summary Guide Background Technical Report Background Technical Report Sherford, Plymouth

Sherford, Plymouth - The Plymouth Local Development Framework identifies new district centres to accommodate key facilities that serve (and generate employment for) large areas of the city. The new western regional centre is located close to the rail network and at the intersection of two strategic roads.
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Longbridge, Birmingham - The Longbridge (Birmingham) regeneration project includes leisure, health and education facilities located near to a public transport node on an inter-town corridor. These facilities will provide an accessible focal point for the redevelopment and the surrounding neighbourhoods.
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Greater Manchester - One priority of the Association of Greater Manchester Authorities' transport strategy is to improveme accessibility to key facilities and employment from areas of significant deprivation, so as to maximise impact on social inclusivity, employment levels and productivity.
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