Assessing the Impact of Local Transport Policy Instruments.

This working paper brings together some relevant material to assist the process of assessing local transport policy instruments. The paper was written with the support of the DETR, but is unofficial. It is intended to be a helpful resource document for local authorities who have indicated in the past a need for guidance in where to look for evidence on the diverse range of transport policy instruments referred to in the White Paper (CM3950). The authors would be grateful for feedback and comments. This document is not intended to be a complete description of the local transport plan process (for that, see the Local Transport Plan Guidance). Nor does this note aim to give a comprehensive review of the appraisal requirements for Local Transport Plans (for that, see Annex E of the Local Transport Plan Guidance and, where relevant, the Guidance on Methodology for Multi-Modal Studies). Important elements in the LTP process including the combination of a set of individual policy elements into a strategy, and the activity of public consultation are not considered. Nor do we consider the specification of problems or the set of objectives within which local transport planning is currently taking place – for these, see for example DETR, 2000. The focus of this piece of work is on assessment of the impact of individual instruments within an urban context. Specifically it considers their effects in terms of:- their impact on transport supply their impact on transport demand their final outcome in terms of their transport, environmental and other impacts When considering policy instruments which impact on urban transport systems, there comes a point at which the impacts and interactions of policies become extremely complicated. At some point, modelling becomes an important part of the assessment process, depending on:- − the capital and recurrent costs at stake − the size of the impact on users and other affected parties, which can be large without the capital costs being large − data availability and the costs of obtaining data for modelling − the ability of a model to represent the policy tool under consideration and the cost of model development. Policy initiatives such as major infrastructure investment, road user charging schemes, or significant roadspace reallocation schemes will require model-based approaches. This note may therefore be useful in one of two contexts firstly, where the intervention is not sufficiently large or significant to warrant a model-based approach, and secondly, to aid a rough calculation at an early stage so as to enable an initial assessment to be made which can then be investigated further. In the next section, we provide a brief generic review of the supply and demand issues so as to give some background to the general analysis and show how second round effects (supply/demand interactions) can be significant in determining the final equilibrium. We also comment on generic appraisal issues. In section three we provide a short review of eleven of the most important policy investments and their supply and/or demand effects. Where possible we have provided approximate indications of their impact, but these should not be interpreted as accurate and applicable to all situations. Finally, in Appendices we provide a reference list of some sixty policy instruments which we have identified in literature and other surveys, a note on elasticity methods for demand estimation, and a note on appraisal practice.