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The following summarises the findings of a recent project. Thanks to all who contributed to the review stages through this and other e- mail groups. ===================================================================== This note describes a study carried out recently by MVA and David Simmonds Consultancy for the Department of the Environment, Transport and the Regions, into the land-use impacts of parking restraint, particularly in city centres. The study involved two literature reviews - one looking at the empirical evidence relevant to the land- use impact of parking restraint, and the other looking at relevant models and previous modelling results. These were followed by an application of the DSCMOD land-use change indicators model based upon the outputs of the TRAM transport model. The review of empirical evidence found that there have been few studies of the direct impacts of parking restraint, primarily because there have been few cases in which policies of restraint covering all types of parking (on- and off-street, private and public) have been applied on a sustained basis. There does not seem to be any directly observed long-term evidence showing that restraint of parking in itself causes problems such as the decline of traditional shopping centres. However, the balance of the evidence suggests that significant restraint would have a negative effect on retailing and other activities, unless counterbalanced by other improvements. Experience of pedestrianisation indicates that environmental improvements can more than counterbalance reduced accessibility so as to make particular parts of centres more attractive and more successful, though the changes involved may involve complex patterns of gains and losses. The review of modelling found that the availability of parking is generally treated by fairly simple cost and time elements in the transport components of land-use/transport interaction models. A range of models capable of responding to such elements is considered, and available results (from the previous MVA/DSC study within this programme, and from the ISGLUTI project) are summarised. Extreme caution needs to be exercised in generalising from these results, but typical impacts are limited decentralisation of employment with mixed impacts on household and population distributions. None of the models considered has explicitly represented parking as a use of land or of floorspace. The TRAM+DSCMOD land-use indicators are the results of a simple static land-use model linked to the TRAM transport model. TRAM was developed by MVA earlier in the present programme of research, as a tool for analysis of parking and traffic restraint. (Descriptions of DSCMOD and of TRAM can be found in Roberts and Simmonds, 1997, section 4, and in Bates et al, 1997, respectively.) The results of the Do-Maximum strategy show an insignificant move of households into the Central Area of the Study Area city (Bristol), and a small outward move of employment; these are rather more negative for the Central Area than the previous START+DSCMOD results. The Do- Something strategy, in contrast, indicates a very slight growth in Central Area employment. The detailed results show marked differences within different zones of the Central Area. The main conclusions drawn are 1 that any major schemes of parking restraint should be accompanied by careful monitoring and analysis of longer-term effects, and 2 that further modelling work appears appropriate to identify the expected effects of such policies and of other associated measures (for example, to offset the negative impact of parking restraint by making the centre more attractive in other ways). Such modelling should move on from static indicators of land-use impact to the use of dynamic models which can more explicitly consider the processes of urban change. References ---------- Bates, J, A Skinner, G Scholefield and R Bradley (1997): Study of parking and traffic demand 2: a Traffic Restraint Analysis Model (TRAM). Traffic Engineering & Control, March 1997, pp 135-141. Roberts, M and D C Simmonds (1997): A strategic modelling approach for urban policy development. Traffic Engineering & Control, July/August 1997, pp 377-384. Further information ------------------- A paper is being prepared for publication. For further information on the project summarised above, please contact Ben Still or David Simmonds at the address below. The project was part of a wider study of parking and traffic demand; for further information on this, please contact Denvil Coombe at MVA ([log in to unmask]). Note ---- The views expressed are those of the consultants (MVA and David Simmonds Consultancy) and are not necessarily those of the Department of Environment, Transport and the Regions. [end] David Simmonds Consultancy 10 Jesus Lane Cambridge CB5 8BA England Phone +44(0)1223 316098 Fax +44(0)1223 313893 e-mail [log in to unmask] %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%