Problems of Land Use and Transport

In their review of the historical development of land use transport studies in the United Kingdom, Solesbury & Townsend (1970) conclude "that activity and transport systems together create and also satisfy the travel demand, and that both are variables. The preparation of land use and transport plans must, therefore be a closely interwoven process ....." However they found that there were several reasons why land use and transport planning had not been fully integrated in the past and why the intregration would be difficult in the future. These reasons can be summarised as, the separate responsibilities of land use and transport planners, the lack of and accuracy of data, trend forecasting of land use, rather than control over development (due to the North American origins of transport planning techniques), and the lack of appreciation of the sensitivity of one variable to another. These and other factors affecting the integration of land use and transport planning will be dealt with in this chapter.

Due to the influence of the North American studies, the first land use transport studies In the U.K. were extremely one sided. Land use was taken as an exogenous variable. The land use projections used were those contained in the existing development plans which covered the area of their study. They merely pieced these together jigsaw fashion. Later it was realised that this procedure was unsatisfactory since, as Jamieson et. al. (1967) demonstrated in a theoretical study, "Although many of the costs of a major development are not significantly affected by the planning layout, this study demonstrates that transportation costs can vary significantly". That is, an optimum transport pattern requires the planning of both the land use and transport systems.

The proper integration of the two planning processes has been and is hampered by several factors. The first is that the two activities have been carried out by two separate professions. Transport planning by Civil/ Highway Engineers, and land use planning by Town planners. This has created a position where the participants in a land use/transport planning study are unlikely to be familiar with all the relevant interactions involved due to their solely "engineering" or "planning" background. "The opportunities for cross links between the land use and transport analyses are multiple, but the techniques appropriate to the organization and management of such multi-disciplinary exercises are only slowly developing" (Solesbury & Townsend 1970).

Another related factor is that although land use and transport planning are both the responsibility of the local authority they are discharged by separate departments under separate committees. This has resulted in a minimum of co-ordination between the two processes and it is far from the required integration. Re-organisation of local government may provide an opportunity to overcome this problem, however the indications are that it will not be taken up. The Patterson report on management structures for the new local authorities in Scotland (Working Group on Scottish Local Government Management & Structures 1973) suggests that land use planning should come under one of the policy committees whilst transport provision and presumably its planning should come under one of the service committees.

At a more technical level there is a problem of incompatibility between the levels of detail of data used in the two different planning processes. A transport study will generally require a level of data from the planning departments in the area it covers which the departments themselves do not use, especially in the forecasts of future land use and socio-economic patterns within the small zones used by the transport planners. If the development plan is not being renewed at the same time as the transport plan either a non-statutory review has to be made of the development plan, or predictions must be made on the basis of the best estimate of current trends. Neither is very satisfactory as they both tend to lead to a situation in which the planning departments are not committed to the land use input to the transport plan. This will undermine confidence in the transport plan.

Related to this problem of different levels of detail in data, is that of accuracy and how changes in input will affect the output. To date very little is known about the extent to which divergencies can be allowed in the land use pattern before the transport pattern is seriously affected. This means that as yet there can be little guidance from the transport plan as to how strictly land use patterns must be enforced by development control because of the transport plan. There is also little understanding of the effects which even small changes in transport networks have on land uses.

So far in this analysis transport, land use and their interaction have been considered within a static framework. However in the 'real world' transport and land use interact dynamically. Changes in land use produce changes in the demand for transport and changes in transport infrastructure, or more correctly changes in accessibility, will tend to produce changes in land use. Very little is known about this effect let alone is anything done. "In fact, even a methodology for analysing the impact of transportation on the economic and population growth of a region seems to be lacking". (Rama Sastry 1973)

When more is known, it should be possible, and indeed it will be highly desirable, that transport planning should be used as a tool of the land use planner. Potentially the control of accessibility, and consequently of demand for land use change, is one of the most powerful tools in the land use planners cupboard.