Does the current traffic impact assessment (TIA) process followed in South Africa encourage unsustainable transport planning?

Abstract

Traffic Impact Assessments (TIAs) analyse the impact of new developments and land use zoning changes on traffic of the surrounding road network. These assessments play a key role in transportation planning and assist in predicting future transport needs. TIAs in South Africa are required to be prepared according to national TIA guidelines, or local variants thereof. This paper considered the implementation of South African TIA guidelines through a case study analysis of the TIAs of five gated suburban residential developments in Cape Town, South Africa. The level of detail of discussions of private vehicle transport, non-motorised transport (NMT), and public transport was investigated. This desktop TIA analysis of TIAs was augmented by a survey of transport engineers that evaluated the level to which sustainable transport planning is facilitated by South Africa’s TIA process. The five TIAs focussed on private vehicle traffic impacts, with detailed capacity analyses, parking discussions, and road upgrade recommendations. NMT and public transport needs were largely overlooked. This supports findings of the literature review of international TIA guidelines, which found that South African guidelines require comparatively little focus on public transport modes. Furthermore, survey results indicated that transport practitioners felt that TIA requirements in South Africa place minimal emphasis on sustainable transport, despite practitioners acknowledging the importance of these modes. This paper provides input for future South African TIA guidelines by emphasising limitations of not incorporating sustainable transport planning and need to move away from vehicle-centric planning.