1. Introduction
The existence of transportation infrastructure in both developed and developing nations, regardless of size or location, has numerous beneficial impacts on economic prosperity, urban growth, tourism, and equity. It has substantially reduced prices and successfully bolstered levels of investment [1], commerce [2], and output [3]. According to Rozenberg and Fay [4], low- and middle-income countries will need to dedicate a portion of their gross domestic product (GDP) each year, ranging from 0.5% to 3.3%, which translates to an estimated sum of US$157 billion to US$1 trillion, for the purpose of developing new transportation infrastructure by 2030. According to Roberts et al. [3], it is recommended that an annual allocation of 1.1% to 2.1% of GDP is required to maintain and develop existing and future transportation infrastructure. Santamaria-Ariza et al. [5] highlighted that in countries with well-developed transportation networks, such as European nations, the expenses related to upkeep and repairs are more significant than the cost of new investments. Neglecting routine maintenance not only results in below-average performance but also increases overall expenses by 50% [4], making the problem worse.
Transportation networks cover extensive geographical regions, rendering each infrastructure asset vulnerable to a range of forces, such as
floods, earthquakes, tsunamis, landslides, storms, wildfires, and excessive temperatures. The convergence of this peril, along with the inherent vulnerability of transportation infrastructure, has already led to substantial monetary damages. Koks et al. [6] found that surface and river floods contribute to over 73% of the global estimated annual damages (EADs) caused by direct natural hazard damage to road and railway systems. The projected damages can range from US
$3.1 to US
$22 billion. The researchers have also computed that EADs can represent around 0.5% to 1% of a nation’s GDP on a yearly basis. This quantity is almost equal to the financial resources designated for the progress and maintenance of the national transportation system [5]. Natural hazards not only result in the destruction of physical assets but also hinder the functioning of infrastructure services, leading to significant repercussions for enterprises, government and non-government organizations, and individuals. According to research by Hallegatte et al. [7], the World Bank estimates that the yearly impact of transport infrastructure disruption in low- and middle-income countries on the capacity utilization rates of enterprises is
$107 billion. The repercussions resulted in monetary losses and the delay of supply and deliveries. The analysis neglected to consider the long-term ramifications, such as reduced global competitiveness, that highlight the substantial costs linked to malfunctioning infrastructure networks.
The management of transportation infrastructure systems is anticipated to face increased difficulties as a result of the escalating frequency and severity of extreme weather events linked to global warming, which is caused by human activities such as the emission of carbon dioxide and other greenhouse gases [8]. The World Meteorological Organization (WMO) has provided an insight into the increasing influence of weather-related disasters from 1970 to 2019 [9]. The World Meteorological Organization (WMO) has recorded a substantial escalation in economic losses, multiplying by a factor of seven from the 1970s to the 2010s. Based on the data, the mean daily losses throughout the duration of ten years from 2010 to 2019 amounted to US$383 million. This represents a sevenfold increase compared to the losses incurred from 1970 to 1979, which amounted to a total of US$49 million. Multiple studies have demonstrated the immediate and indirect impacts that natural disasters have on global transportation systems, which has sparked interest among scholars and governments worldwide. As a result, significant resources, such as knowledge, time, and money, have been dedicated to improving the ability to withstand and manage risks in existing and future transportation infrastructure systems.
The objective of engineers, policymakers, and operators of transportation infrastructure is to construct and uphold systems that possess the qualities of sustainability and resilience [10]. Various approaches and strategies have been devised to integrate these two concepts, with some complementing and others conflicting with one another [11]. While certain individuals perceive resilience and sustainability as mutually supportive objectives, others view them as separate and perhaps conflicting in terms of design [12]. While the systematic application of these concepts has been observed in the construction of buildings [13], it is challenging to optimize the performance of large-scale transportation infrastructure systems and assets using the same principles [14]. An essential initial stage in integrating the two ideas into a cohesive framework and worldwide measurements is to enhance the climate-resilient efficiency of transportation assets such as bridges while considering the environmental impacts produced by factors like overall carbon emissions during the lifespan, in addition to prices.
The transportation sector is accountable for over 70% of global greenhouse gas (GHG) emissions. The primary cause of this is predominantly attributed to the establishment and maintenance of transportation infrastructure [15]. In order to evaluate the environmental effects, different greenhouse gases are measured in terms of their carbon dioxide (CO2) equivalents [16]. According to the ASCE Report Card History [17], an estimated $125 billion is needed to repair the 36% of bridges in the United States that are in need of restoration, as stated by Lehman [18]. According to Wardhana and Hadipriono [19], hydraulic phenomena, such as floods and scour, account for around 53% of bridge failures. The present value of this figure is anticipated to increase as a result of the worsening environmental circumstances. The importance of infrastructure in meeting sustainable development goals, such as achieving emission targets by 2030 and reaching net zero emissions by 2050, cannot be overstated. The cited figures are replicated worldwide using GDP, as noted by the European Commission [20] and Mitoulis et al. [11]. The 2020 Medicane Ianos, which hit Greece and impacted a considerable region of the country, exemplifies a recent occurrence of a flash flood that caused severe destruction to bridges and transportation networks. Three additional bridges sustained substantial damage, while five bridges were completely or partially obliterated [21].
Khanna et al. [22] and the Ecochain Mobius platform provide a comprehensive description of the 15 environmental impact categories in life cycle assessments (LCAs). They discovered that these categories encompass resource depletion, climate change, and human health implications. Furthermore, their research emphasizes the significance of taking into account all environmental effects when conducting life cycle assessments (LCAs) in order to effectively evaluate the sustainability of products and processes. Implementing eco-friendly approaches in machining processes can result in substantial reductions in carbon emissions and energy consumption. The case study emphasized the significance of taking into account the complete life cycle of a product when evaluating sustainability criteria. In the field of building, it has been discovered that environmental harm is typically measured using the Global Warming Potential (GWP). This metric is used to assess the extent of
climate change resulting from the emission of greenhouse gases. By integrating sustainable practices into machining operations, organizations can simultaneously decrease their environmental impact and enhance their overall efficiency and competitiveness in the market.
Mitoulis et al. [23] discovered that integrating sustainability and climate resilience measures into decision-making processes for the recovery of transport infrastructure assets can result in outcomes that are both more robust and environmentally benign. Achilleos et al. [24] discovered that incorporating steel fiber-reinforced concrete mixes in pavement construction is an environmentally friendly approach to address the effects of
climate change on transportation infrastructure. The study conducted by McKenna et al. [25] revealed that the inclusion of end-of-life tire components in concrete production can lead to a substantial decrease in greenhouse gas emissions and energy usage when compared to conventional ways of producing concrete. Sabau et al. [26] discovered that recycled aggregate concrete exhibited markedly reduced carbon emissions in comparison to natural aggregate concrete, particularly when the amount of cement used was decreased. Using recycled resources in concrete production can effectively decrease the environmental impact of construction activities. According to Reza et al. [27], climate change is projected to have substantial adverse effects on the longevity and performance of paved roads, resulting in higher expenses for maintenance and a reduced lifespan. The study utilizes the Em-LCA approach, which offers a complete framework for assessing the sustainability of infrastructure systems in the context of climate change. It emphasizes the significance of including environmental impacts in infrastructure planning and design. According to Wang et al. [28], the establishment of highways in the southwest area of
China had a substantial impact on the release of carbon dioxide into the atmosphere. The research emphasized the immediate requirement for sustainable methods in infrastructure development to alleviate the environmental consequences of transportation projects.
Somboonpisan and Limsawasd [29] discovered that including environmental factors in bid evaluations can effectively foster sustainability in highway construction projects. This strategy can result in the development of more robust infrastructure that is more capable of withstanding the difficulties presented by climate change. Nahangi et al. [30] discovered that the bridge’s embodied greenhouse gas emissions were considerably greater than previously calculated, emphasizing the need for precise evaluation of environmental effects in infrastructure endeavors. This study highlights the necessity for enhanced techniques in assessing and reducing carbon emissions in construction endeavors to tackle the increasing apprehensions regarding climate change. Dong et al. [31] discovered that bridges that are susceptible to seismic activity face a higher likelihood of being damaged as a result of climate change-related hazards, such as flooding and severe weather events. The study emphasizes the significance of integrating these ever-changing elements into infrastructure planning and design to guarantee long-term durability and adaptability. Dong et al. [32] discovered that the rising
occurrence and severity of natural catastrophes caused by climate change present a substantial risk to the long-term viability of highway bridge networks. The study also emphasized the significance of taking proactive steps to improve the resilience of transportation infrastructure in response to these issues.
Mackie et al. [33] discovered that climate change is causing extreme weather events to occur more frequently and with greater severity. This, in turn, is presenting considerable obstacles to the ability of transport infrastructure to withstand and recover from these difficulties. The study also emphasizes the significance of integrating sustainability criteria into the evaluation of bridge performance during seismic events to guarantee its long-term sustainability. Noland and Hanson [34] discovered that the utilization of construction equipment significantly contributes to onsite emissions. In fact, it can constitute up to 20% of the overall emissions of a project when employing conventional equipment. The characteristics of the site have a significant impact on the quantity of these emissions, according to Barandica et al. [35]. When comparing flat sites to hilly ones, the disparity might be as significant as 30-fold. This emphasizes the significance of taking geographical considerations into account when designing and implementing road improvements in order to reduce greenhouse gas emissions.
Somboonpisan and Limsawasd [29] discovered that the utilization of hybrid engines or other environmentally friendly alternatives can effectively
lower equipment emissions by as much as 50%. This reduction in emissions ultimately results in a decrease in the overall carbon footprint of building projects. Mackie et al. [33] discovered that transportation usually accounts for approximately 4% or less of average haulage requirements. However, it is anticipated that this proportion will rise as
climate change continues to impact infrastructure. The study also emphasized the significance of adopting sustainable practices in transportation to alleviate these effects. Wang et al. [28] discovered that the production of materials is responsible for around 80% of emissions, whereas material transportation and onsite activities contribute only 3% and 10% of total emissions, respectively. The data indicate that directing efforts towards decreasing emissions during the manufacturing phase could have a substantial effect on the total carbon dioxide emissions in highway buildings.
Liu et al. [36] found that steel and cement are responsible for 98% of the carbon emissions generated during the construction of bridges. Nevertheless, these components account for just about 15% of the overall resources utilized. Rock and sand make up 80% of the material, yet they only contribute less than 1% of the total carbon. This suggests that directing efforts towards decreasing carbon emissions, specifically from steel and cement used in bridge construction, could have a substantial influence on the total amount of emissions produced. According to Keolwian et al. [37], bridge projects that utilize low-carbon and high-performance materials can achieve a carbon emission reduction of over 40% compared to conventional options. Although the upfront expenses of incorporating these materials may be greater, the enduring advantages in terms of resilience, upkeep, and ecological impact render them a more sustainable option for forthcoming infrastructure endeavors.
According to Heidari et al. [38], the environmental impact and energy consumption of road surfacing differ based on the specific pavement type utilized. Cement pavement exhibits a reduction in emissions and energy consumption ranging from 12% to 55% when compared to asphalt pavements. According to Santero and Horvath [39], the flexibility of pavement and the decrease in rolling resistance can independently impact emissions throughout the recovery period after a hazard. These impacts can have long-lasting implications for the lifespan of the asset. Nazarnia et al. [40] discovered that the frequency and intensity of flooding occurrences have increased as a consequence of climate change. This has led to the substantial destruction of railway tracks, bridges, and signaling systems. Consequently, there has been a rise in the expenses associated with maintenance, as well as interruptions in the provision of services, and apprehensions over the safety of both passengers and workers. Santamaria-Ariza et al. [5] reviewed the current body of research on the issue to highlight important topics and areas where information is lacking. Their findings offer valuable insights for policymakers and practitioners in the field.
Rattanachot et al. [41] discovered that the adaptation solutions with the highest effectiveness involved the integration of robust design features, intensifying maintenance efforts, and integrating climate change considerations into long-term planning. A study conducted by Arsenio et al. [42] revealed that climate change is expected to exert substantial adverse impacts on Portugal’s transportation infrastructure by the year 2030. The study emphasizes the immediate necessity of implementing adaptation measures and making investments in robust infrastructure to minimize these effects and guarantee that the nation’s transportation requirements are fulfilled in light of a shifting
environment. Mesdaghi et al. [43] discovered that institutional ties have a significant impact on the effectiveness of climate adaptation methods in the transport industry. The study emphasized the significance of collaboration and coordination among many stakeholders to effectively tackle the problems presented by climate change for transport infrastructure. Sanchez and Govindarajulu [44] discovered that the incorporation of blue-green infrastructure into urban planning can greatly enhance the ability of transport systems to withstand the effects of climate change. The case studies of Chennai and Kochi showcased the effectiveness of integrating nature-based solutions, such as green roofs, permeable pavements, and rain gardens, in adapting to flooding, improving water quality, and offering other advantages for urban regions.
Niskanem et al. [45] discovered that the group of individuals and organizations involved in Sweden’s transport infrastructure sector, known as the discourse coalition, has changed its focus to prioritize sustainability and resilience. This move is a response to the difficulties presented by climate change. This trend indicates an increasing acknowledgment of the necessity for proactive actions to reduce the effects of climate change on transportation networks. According to Blackwood et al. [46], the inclusion of natural-based solutions, such as green infrastructure and ecosystem restoration, can effectively reduce the impact of climate change on rail infrastructure. According to Markolf et al. [47], transportation networks are becoming more susceptible to the impacts of climate change as a result of more frequent and intense weather events.
Chatzichristaki et al. [48] reported that the flash flood on 22 November 2013, in Rhodes Island, caused significant damage to roads, bridges, and other transportation infrastructure. The study also highlighted the need for improved infrastructure design and maintenance to mitigate the effects of severe weather events in the future. Jones et al. [49] conducted a study that found that climate change-induced extreme weather events have resulted in substantial disruptions to transportation networks worldwide. In 2017, the City of Atlanta observed an increasing frequency of severe weather events, such as hurricanes and heavy rainfall, which have
caused significant damage to the city’s roads, bridges, and public transportation infrastructure [50]. In 2015, the City of Atlanta conducted a study and concluded that its transportation system is particularly vulnerable to extreme weather events, such as hurricanes and flooding [51]. The study highlights the importance of implementing sustainable transportation options to mitigate these risks and adapt to a dynamic
environment. Mehare and Joshi [52] found that urban areas with high population density and extensive paved surfaces are more susceptible to the impacts of the urban heat island (UHI) phenomenon. This is because these regions have less vegetation and absorb more heat. Habermann and Hedel [53] found that severe weather events, such as storms and flooding, have significantly disrupted transportation networks, resulting in economic losses and safety hazards.
Although various studies have been undertaken worldwide on adaptation techniques to reduce the effects of climate change on transportation infrastructure, there has been no systematic analysis of the specific impacts of these measures in Lagos, Nigeria. The majority of articles published in Lagos, Nigeria, about transportation infrastructure primarily examine the effects of climate change on flooding and erosion [54] and the Centre for Research on the Epidemiology of Disasters [55] as shown in Table 1, while neglecting to discuss the implementation of adaptation techniques that can effectively mitigate these effects. This study aims to address the lack of understanding by investigating the efficacy of several adaptation measures in reducing the impact of climate-related risks on transportation infrastructure in Lagos, Nigeria. The second phase of this study will examine and assess the effects of previous climate change on transportation infrastructure, strategies for adapting to climate change-related damages to transportation infrastructure, and the consequences of future climate change on transportation infrastructure in Lagos, Nigeria. This section aims to establish a foundation for proposing a comprehensive framework to adapt Lagos’s transportation infrastructure to future climate change scenarios. It will achieve this by developing strategic theories to analyze the impacts of climate change and formulating strategies and policies to assess the effectiveness of different adaptation measures. The ultimate goal is to devise sustainable solutions that enhance Lagos’s transportation infrastructure’s resilience to climate change. The objective of this study is to provide policymakers and stakeholders with valuable insights into the most efficient strategies for safeguarding transportation infrastructure against the impacts of climate change. This study aims to identify effective adaptation solutions that can be used to guide future planning and investment decisions, with the goal of ensuring the long-term resilience of Lagos’s transportation networks. The final phase of this study focuses on providing closing remarks and suggesting future research directions that will enhance Lagos’s transportation infrastructure’s resilience in the face of climate change-induced challenges. We will present recommendations for policy reforms and investment priorities to facilitate the adoption of these adaptation strategies.
5. Policy Implications for the Transportation Scenarios for Adaptation Strategies Proposed in Lagos, Nigeria
The policy consequences of the transportation scenarios outlined in Lagos’s adaptation strategy are substantial. First and foremost, it is important to have extensive infrastructure development in place to effectively support the transportation systems described in these scenarios. This includes the allocation of resources towards the development and enhancement of road networks, public transportation systems, and intermodal connections. The objective is to guarantee the smooth and environmentally friendly transportation of goods and individuals. Efforts should focus on giving priority to the implementation of clean and
renewable energy sources for transportation in order to decrease carbon emissions and alleviate the effects of climate change. The policy implications of the transportation scenarios for the proposed adaptation solutions in Nigeria, as shown in Figure 4, are as follows:
5.1. Policy Considerations for Improving Road Network Resilience in Nigeria by Implementing Proper Drainage Systems and Slope Stabilization Measures
5.1.1. Enhancing Emergency Response and Recovery Mechanisms Policy
To enhance the resilience of road networks in Nigeria, it is necessary to establish a strong emergency response and recovery processes. This includes the establishment of effective communication lines, the training of emergency personnel, and the coordination with pertinent agencies to promptly resolve any disruptions resulting from natural disasters or accidents. Allocating resources towards acquiring cutting-edge technology and state-of-the-art equipment for emergency response teams can enhance their efficiency in handling interruptions in the road network. Implementing routine drills and simulations can guarantee that all parties involved are adequately equipped to manage unexpected occurrences and mitigate the consequences for transportation systems.
5.1.2. Implementing Regular Maintenance and Inspection Programs Policy
Implementing thorough maintenance and inspection protocols is crucial for guaranteeing the prolonged resilience of road networks. Regular inspections can help identify potential vulnerabilities in drainage systems, pavement conditions, and other critical elements of infrastructure. To mitigate interruptions and minimize the occurrence of unplanned breakdowns, road authorities might adopt proactive methods to address these concerns. Engaging in regular maintenance activities, such as repairing potholes and controlling vegetation, can efficiently maintain the safety and efficiency of road networks while reducing the likelihood of disruptions caused by worsening conditions. The use of advanced technologies such as remote sensing and data analytics can enhance the efficiency of maintenance activities by providing real-time monitoring and predictive analysis. This allows road authorities to efficiently prioritize and allocate their resources, ensuring that crucial infrastructure elements are consistently inspected and repaired promptly to avert any significant hazards.
5.1.3. Integrating Climate Change Adaptation Strategies and Policy
Incorporating climate change adaptation strategies into road network planning and design in Nigeria is essential due to the ongoing and severe difficulties posed by climate change to infrastructure. This can involve implementing strategies such as constructing raised highways, using flood-resistant materials, and enhancing stormwater management systems to strengthen the ability of road networks to withstand severe weather conditions. Utilizing green infrastructure measures such as rain gardens and permeable pavements can effectively alleviate the consequences of intense rainfall and minimize the likelihood of floods.
5.1.4. Strengthening Infrastructure Maintenance and Rehabilitation Policy
To enhance the overall resilience of road networks to extreme weather events, it is important to prioritize regular maintenance and prompt rehabilitation. This will avoid deterioration and limit disruptions caused by drainage issues or unstable slopes. This encompasses routine inspections and maintenance of drainage systems, along with adapting to any possible weaknesses in the road infrastructure. It is possible to significantly increase the resilience of road networks to withstand erosion and landslides brought on by extreme weather conditions by using cutting-edge techniques like slope stabilization measures.
5.1.5. Promoting Sustainable Infrastructure Development Policy
Implementing efficient drainage systems and slope stabilization policies is vital for sustainable infrastructure development in Nigeria, as it enhances the resilience of road networks. Implementing these techniques can mitigate erosion and landslides, therefore maintaining the durability and effectiveness of roads even in the presence of fluctuating climate conditions. Integrating renewable energy sources into infrastructure projects can enhance sustainability endeavors and diminish greenhouse gas emissions.
5.1.6. Adapting to Climate Change Impacts Policy
Nigeria can enhance its ability to cope with shifting climate patterns and minimize the susceptibility of road networks to severe weather events like intense rainfall and landslides by implementing adequate drainage systems and slope stabilization measures. Adopting climate-resilient road designs, such as elevated or reinforced infrastructure, can also aid in reducing the effects of increasing sea levels and heightened flooding. The implementation of a policy that incorporates green areas and flora along roadways can yield natural cooling effects, mitigate the urban heat island phenomenon, and enhance air quality.
5.1.7. Ensuring Efficient Transportation Networks Policy
By installing robust drainage systems and enacting strategies to stabilize slopes, the negative impacts of heavy rainfall and landslides on roads can be substantially reduced. By investing resources in advanced smart transportation technologies, such as real-time traffic monitoring and intelligent traffic management systems, it is possible to improve the efficiency of transportation networks and reduce congestion.
5.2. Policies for Developing Alternative Transportation Modes to Reduce Road Network Vulnerability
In order to kickstart the advancement of different modes of transportation in Lagos, Nigeria, it is crucial to invest resources towards building infrastructure that supports non-motorized ways of transportation, such as cycling and walking. This involves the creation of dedicated bike lanes, pedestrian pathways, and the improvement of sidewalks to encourage the use of these eco-friendly transportation options within the city.
Moreover, governments should give precedence to the expansion of public transportation options, such as buses and light rail systems, with the aim of providing economical and effective alternatives to driving. By investing in a reliable public transportation infrastructure, a larger portion of the population will have access to key areas of the city without relying on personal vehicles. This will lead to a reduction in traffic congestion and pollutants generated by vehicles on the road.
In order to encourage individuals who still rely on driving to adopt electric vehicles and other environmentally friendly energy sources, it is essential to develop incentives or advantages. This could involve offering incentives for the purchase of electric vehicles, implementing a city-wide infrastructure of charging stations, and creating legislation that prioritizes environmentally friendly vehicles in urban planning decisions. Lagos can reduce its susceptibility to road network vulnerabilities and improve air quality and the overall quality of life for its residents by promoting the use of sustainable transportation options.
5.3. Policies for Incorporating Climate Change into New Transportation Infrastructure Design and Construction
It is imperative that these policies give utmost importance to sustainability and resilience, considering the city’s susceptibility to severe weather events and the increasing sea level. Additionally, it is crucial for them to take into account the significance of advocating for public transportation and non-motorized means of transportation in order to mitigate greenhouse gas emissions.
Furthermore, the rules should have provisions to guarantee that new infrastructure is constructed using materials and procedures that minimize the environmental impact and carbon footprint. This may entail utilizing recycled materials, adopting environmentally friendly construction methods, and integrating renewable energy sources into transportation networks.
It is imperative for these policies to engage stakeholders from many sectors, such as government agencies, private firms, community organizations, and academic institutions. Collaboration among these sectors is crucial for creating inventive solutions that tackle the concerns of climate change while simultaneously fulfilling the increasing transportation demands of Lagos’s fast-rising population.
5.4. Policy Options for Improving Transportation Agencies’ Data Collection and Analysis to Monitor and Respond to Climate-Related Events
An effective policy approach would involve allocating resources towards the adoption of cutting-edge data gathering technology, such as remote sensing and GIS mapping, in order to enhance the precision and promptness of climate-related data. These devices can offer up-to-the-minute data on weather patterns, instances of flooding, and other climate-related occurrences, enabling transportation organizations to make better-informed choices in addressing emergencies.
Another policy alternative is to forge alliances with nearby colleges and research institutions in order to bolster data analytics capabilities. Transportation agencies can enhance their understanding of the effects of climate change on infrastructure and devise resilience measures by partnering with climate science and environmental monitoring professionals. Moreover, these collaborations can enhance the agency’s ability to develop and maintain the necessary resources for continuous data gathering and analysis.
Finally, incorporating climate change considerations into long-term transportation planning procedures helps guarantee that infrastructure investments are able to withstand future climate-related catastrophes. To proactively address vulnerabilities and limit the possible implications of extreme weather events on their operations, transportation agencies can integrate climate risk assessments into project evaluations and prioritize adaptation measures. Implementing this comprehensive strategy can contribute to the development of a transportation system in Lagos, Nigeria, that is both environmentally friendly and capable of withstanding challenges.
