Sustaining critical transport infrastructure space in megacities: multimodal assessment of railway and road systems in Kano & Lagos — Nigeria

Globalisation has the most tremendous negative effects on the changing landscapes of many cities because of the roles of cities as the de facto economy and haven of liveable socioeconomic advantages. As the urban population grows, particularly in developing countries' mega-cities where transport development faces the most complex challenges, a more sophisticated framework of assessment of critical transportation infrastructure and transportation planning is required. This research aims to investigate transport effects of the complex web of interactions of urban chain processes to bring about a more sustainable (and resilient) transport infrastructure development of mega-cities. The interdisciplinary research concepts which incorporate the development of scenario-based applications and prediction techniques involving qualitative and quantitative frameworks were applied to the two Nigerians most populous cities (Lagos and Kano). The framework includes the analysis of spatial-temporal relationship of transport space and urban land use change, congestion and accessibility, sustainability paradigm and themes and ordering of priorities of the intervention policies based on transportation demand management objectives. Data sources include Landsat images, traffic and demographic data, transportation infrastructure inventories, and collaborative engagement with stakeholders and policymakers via questionnaires, interviews, and checklists. First, spatial-temporal analysis was carried out using remote sensing GIS software for land use classification and CA-Markov model implemented in IDRISI SELVA for temporal prediction and its suitability quality. Next is the assessment of accessibility and congestion pattern of the two cities using a surrogate multi-layer feed-forward and back-propagation model involving input-output and curve fitting (NFTOOL) implemented in artificial neural network wizard of MATLAB. Also, the sustainable paradigm and themes were carried using questionnaire and interview instruments and analysed respectively using SPSS and NVivo softwares. Finally, the priorities of intervention policy decision and quality of infrastructure and services were analysed using hybrid SERVQUAL-AHP models. The spatial-temporal analysis of the two cities produced patterns of rising trends for transport and built-up areas while the other land use classes are receding. For example, Kano transport space had grown from 137km$^2$ in 1984 to 290km$^2$ in 2019 while that Lagos grew from 337km$^2$ to 535km$^2$ in the same period. The dynamics model predicts spatial land requirement of Kano city for transport to reach 410km$^2$ in 2050 while Lagos will be needing 692km$^2$ in the same period. Future prediction of the two cities will be highly unsustainable for transport infrastructure. The congestion profile results put the two cities within congestion indices ranging from 7.5 to 10 on a maximum scale of 10, indicating extreme traffic congestion regimes and inaccessibility in the two cities. The sustainability paradigm comprising literacy, sustainable choices and indicators of sustainable transport are below average exposing poor development in the area. Also, the thematic analysis revealed the preponderance of more negative sentiments from the interview over statements of optimism and progress and it corroborates the findings of sustainability paradigm. Finally, satisfaction quality assessment produced low quality scores of 48% and 49% for Kano and Lagos cities respectively. AHP equally allocated more weight to tangibility which defines infrastructure and service qualities. These values are suggestive of the necessity to infrastructure, public transit systems and management of transport demand in the decision policy making. To deal with rising urbanization trends in Nigerian cities and maintain liveable and accessible urban environments, aggressive push—and—pull policies that improve and increase transport infrastructure quality and drive sustainable transport, promote modal split, reduced motorization, and access control is recommended

Optimum Portland Cement-Guinea Corn Husk Ash Blend as Filler in Hot Mix Asphalt

Abstract- Dwindling natural resources and the negative environmental impact that comes with the industrial processing of construction materials are the driving forces to man’s quest for cleaner (green) and cheaper alternative construction materials. Among such alternatives include agricultural wastes. Guinea corn husk ash (GCHA), an agricultural waste obtained from the incineration of Guinea corn husk, has shown potentials of been used as filler material in hot mix asphalt due to its pozzolanic properties. Thus, this research aims to assess the strength and durability properties of hot mix asphalt with the incorporation of GCHA as a partial replacement for filler (cement). Marshal mix design method was used to determine the optimum bitumen content (OBC) at no GCHA content (control mix) within the bitumen content range prescribed by Nigerian general specifications for roads and bridges (NGSRB) for bituminous courses in flexible pavements. This OBC was used to determine the optimum GCHA by replacing the primary filler with GCHA up to 45% in increments of 5%. Marshal indices and volumetric properties of samples prepared at each replacement level were determined according to relevant standards. Mixtures containing up to 20% Portland cement replacement with GCHA were found to produce competitive results against the control mix (only cement as filler). Thus, Marshall indices and volumetric properties of mixtures containing up to 20% cement replacement GCHA satisfy the minimu

Neural Network Approach to Modelling Transport System Resilience for Major Cities: Case Studies of Lagos and Kano (Nigeria)

Congestion has become part of everyday urban life, and resilience is very crucial to traffic vulnerability and sustainable urban mobility. This research employed a neural network as an adaptive artificially-intelligent application to study the complex domains of traffic vulnerability and the resilience of the transport system in Nigerian cities (Kano and Lagos). The input criteria to train and check the models for the neural resilience network are the demographic variables, the geospatial data, traffic parameters, and infrastructure inventories. The training targets were set as congestion elements (traffic volume, saturation degree and congestion indices), which are in line with the relevant design standards obtained from the literature. A multi-layer feed-forward and back-propagation model involving input–output and curve fitting (nftool) in the MATLAB R2019b software wizard was used. Three algorithms—including Levenberg–Marquardt (LM), Bayesian Regularization (BR), and a Scaled Conjugate Gradient (SCG)—were selected for the simulation. LM converged easily with the Mean Squared Error (MSE) (2.675 × 10−3) and regression coefficient (R) (1.0) for the city of Lagos. Furthermore, the LM algorithm provided a better fit for the model training and for the overall validation of the Kano network analysis with MSE (4.424 × 10−1) and R (1.0). The model offers a modern method for the simulation of urban traffic and discrete congestion prediction

Optimum Portland Cement-Guinea Corn Husk Ash Blend as Filler in Hot Mix Asphalt

Abstract- Dwindling natural resources and the negative environmental impact that comes with the industrial processing of construction materials are the driving forces to man’s quest for cleaner (green) and cheaper alternative construction materials. Among such alternatives include agricultural wastes. Guinea corn husk ash (GCHA), an agricultural waste obtained from the incineration of Guinea corn husk, has shown potentials of been used as filler material in hot mix asphalt due to its pozzolanic properties. Thus, this research aims to assess the strength and durability properties of hot mix asphalt with the incorporation of GCHA as a partial replacement for filler (cement). Marshal mix design method was used to determine the optimum bitumen content (OBC) at no GCHA content (control mix) within the bitumen content range prescribed by Nigerian general specifications for roads and bridges (NGSRB) for bituminous courses in flexible pavements. This OBC was used to determine the optimum GCHA by replacing the primary filler with GCHA up to 45% in increments of 5%. Marshal indices and volumetric properties of samples prepared at each replacement level were determined according to relevant standards. Mixtures containing up to 20% Portland cement replacement with GCHA were found to produce competitive results against the control mix (only cement as filler). Thus, Marshall indices and volumetric properties of mixtures containing up to 20% cement replacement GCHA satisfy the minimu

Optimum Portland Cement-Guinea Corn Husk Ash Blend as Filler in Hot Mix Asphalt

Abstract- Dwindling natural resources and the negative environmental impact that comes with the industrial processing of construction materials are the driving forces to man’s quest for cleaner (green) and cheaper alternative construction materials. Among such alternatives include agricultural wastes. Guinea corn husk ash (GCHA), an agricultural waste obtained from the incineration of Guinea corn husk, has shown potentials of been used as filler material in hot mix asphalt due to its pozzolanic properties. Thus, this research aims to assess the strength and durability properties of hot mix asphalt with the incorporation of GCHA as a partial replacement for filler (cement). Marshal mix design method was used to determine the optimum bitumen content (OBC) at no GCHA content (control mix) within the bitumen content range prescribed by Nigerian general specifications for roads and bridges (NGSRB) for bituminous courses in flexible pavements. This OBC was used to determine the optimum GCHA by replacing the primary filler with GCHA up to 45% in increments of 5%. Marshal indices and volumetric properties of samples prepared at each replacement level were determined according to relevant standards. Mixtures containing up to 20% Portland cement replacement with GCHA were found to produce competitive results against the control mix (only cement as filler). Thus, Marshall indices and volumetric properties of mixtures containing up to 20% cement replacement GCHA satisfy the minimu