This article looks at the ways in which poor or erroneous traffic impact (TI) evaluations occur in a Transport Assessment (TA) report. A TA provides detailed information on a range of transport conditions and related issues for all phases of a proposed building development. A fundamental part of this is the TI study, which assesses the impact of the proposed development on local junctions. A variety of software modelling products is used for this. Problems arise when developer consultants submit poor TI evaluations which make the impact seem less: at a later stage the work needs to be done again. If the original TI study is checked by the local authority, the problem is recognised earlier but the cost of checking is incurred. This paper describes common TI submission errors that occur in using certain software models: most concern measurement errors, lack of subject knowledge or lack of expertise in using the model. A decline in standards of traffic impact studies may be caused by developer consultants trying to save time and money or by public authorities failing to check work being done. The author believes that improvements could be made by consultants training staff better, and local authorities increasing communication and checking procedures, with financial penalties.
Abstract