Abstract
The concept of sustainable transportation in the developing world has become a dominant theme in the discourse of city development practices. There is broad acknowledgment that transportation emissions could increase faster than emissions from other sectors, without aggressive and sustained mitigation policies being implemented. In response to these global efforts, this research sought to add to the existing body of knowledge on ecological traffic management. It used a developing city as a case study to assess the ecological impact of vehicular traffic using new data types and tools. The research also proposes a mathematical solution for designing an ecological-friendly public transportation system while taking account of societal constraints. The study utilises existing congestion and emission indexes to develop a new congestion to emission index to illustrate the ecological impact of general traffic, essential traffic and public transportation traffic in the city of Johannesburg, South Africa. The research also uses an existing public transportation system (Gaubus and Gautrain), which operates in the city of Johannesburg, to improve the robustness of the network. This introduces new boundaries for non-motorised transportation (green tuk-tuk). Using graph network modelling and network metrics, a solution of network augmentation is derived for the network. The results on the ecological impact of vehicular traffic, assessed with new data types and tools, reveals that the national lock-down in 2020 led to reduced emission from transportation and better quality of air. However, introducing a lock-down is not an advisable option to reduce vehicular emissions as this would negatively impact economic activities. The research, however, proposes shifting commuting trips to public transportation or ride-sharing services whenever possible. This would reduce the volume of traffic on highways while also reducing vehicular emissions. Another option could be to distribute working time optimally to reduce morning and afternoon peaks. The results from the ecologically efficient, multimodal network augmentation with societal constraints reveal that non-motorised green mobility services are viable for improving mobility in the city for the first and last mile of commuting trips. The composite costs introduced herein could be used for new routing algorithms, including societal, environmental, architectural contexts, and commuter experiences through ratings. Consequently, the research provides evidence to support decision-making and also advocates for environmentally friendly transportation. The investment in mining and analysing traffic data has a significant role in future mobility planning in both the developed and developing world and, more generally, improves the quality of commuting trips in the city.
Key words: sustainable, ecological traffic management, emission, congestion, transportation.