Tangible Intangible Direct Indirect Damage to road structure Damage to vehicles Damage to utility systems Debris and deposition cleans up cost Cost of traffic/transport disrupt
Background
Road infrastructure is vital to Australia's economy, providing essential connectivity that supports regional transportation and local communities (Merick 2008) With increasing population and economic growth, road networks experience rising demand from freight and passenger transport, driven by higher incomes (Economics 2007) The primary value of roads lies in enhancing accessibility, enabling social connections, facilitating business operations, and supporting collective activities—linking workers, consumers, resources, and markets (Merick 2008) Additionally, other critical infrastructure such as sewer, power, water, and internet services depend heavily on robust road networks Overall, roads are Australia's most essential lifeline, underpinning social development and economic vitality.
Bridges are critical components of road networks, playing a vital role in connecting different routes and reducing traffic congestion, travel time, and distance (Padgett et al 2008; Gentle, Kierce & Nitz 2001; Hallegatte & Przyluski 2010) The value of a bridge consists of two main parts: its construction cost, or asset value, and the economic benefits of accessibility it provides to stakeholders While constructing bridges involves significant financial investment—such as the Yeppen South project, which costs 256 million AUD—the true value extends beyond assets, as bridge closures can isolate communities and hinder economic activity, especially in rural areas According to research, the total economic value of a bridge is often much greater than its initial construction cost, with the adverse effects of disruptions on local communities being difficult to quantify in monetary terms (Hallegatte & Przyluski 2010).
Natural hazards pose significant threats to bridges throughout their life cycle, with the potential to damage both their physical structure and accessibility Even after repair from flood damage, bridges may experience reduced accessibility, disrupting daily activities like commuting, healthcare, and essential services (Greenberg, Lahr & Mantell) Accessibility is crucial for the resilience of local communities, as loss of connectively can delay post-disaster recovery efforts Additionally, the rehabilitation of vital infrastructure such as power, sewer systems, and internet connectivity often depends on intact bridges and road networks.
As a flood-vulnerable country, Australia has suffered from flood events (Guha-Sapir et al
2011) There were 26 main flood events from January 2000 to July 2015 The expenditures that were calculated by the insurance companies for rehabilitation after disasters amounted to
Figure 1.1 Yeppen Bridge in Queensland (Ahmad 2006)
Flood events in Australia have caused significant infrastructure damage, with reported costs reaching 4,329.5 million AUD, according to the Australian Institute of Disaster Resilience (2015) Many bridges were either damaged or destroyed during these floods, disrupting essential transportation routes A Queensland government report highlights that critical road networks were almost always affected in every flood event, emphasizing the widespread impact of flooding on infrastructure resilience and transportation safety (Repo, 2012).
In 2013, the Lockyer Valley region in Queensland experienced damage to forty-two bridges, highlighting the significant infrastructure impact of flood events The economic costs associated with bridge damage are often difficult to predict accurately, as traditional insurance calculations tend to underestimate the true economic losses Insurance companies typically only account for property damages covered under their policies, which fails to capture the full extent of economic disruptions caused by such flood-related infrastructure damage.
Flood as one of the main threats to bridge
More flood events in the near future
Flood events are frequent natural disasters in Australia, with the potential to cause severe damage to road infrastructure According to Hughes (2003), heatwaves and floods are among the most destructive natural hazards impacting roads Geoscience Australia defines a flood as a temporary condition of partial or complete inundation of normally dry land due to overflow from inland or tidal waters caused by rapid surface runoff The origins of floods are diverse, making them a significant concern for infrastructure resilience and planning.
Flooding in Australia occurs from diverse sources such as coastal floods from the sea, fluvial floods from rivers, pluvial floods caused by heavy rainfall, and groundwater floods from below the surface (Klijn, 2009) These floods are widespread across major population centers, with an estimated average annual direct cost of AUD 370 million (BITRE, 2008) Coastal regions frequently experience floods due to the rainy season and tsunamis, impacting infrastructure like bridges Between 1990 and 2015, EM-DAT recorded 42 severe flood events—increasing flood frequency and intensity—resulting in 117 deaths, 89 injuries, and nearly 293,000 people affected, emphasizing the urgent need for flood risk management in Australia.
Figure 1.2 The distribution of flood events in Australia(Australian Government of Geoscience Australia)
The climate report warns that Australia is set to experience more frequent and severe flood and extreme weather events in the near future (Guha-Sapir et al., 2011; Hughes, 2003) The rising intensity and frequency of natural disasters driven by climate change pose significant risks to road infrastructure and increase the potential for substantial losses during these events (Bankoff, Frerks & Hilhorst) Addressing these challenges requires proactive strategies to enhance infrastructure resilience and mitigate climate-related damages.
Extreme weather events, including bushfires, heatwaves, and floods, are projected to increase in frequency and intensity across Australia (Hughes, 2003; EM-DAT Database, 2009) While the overall climate trend indicates drier conditions in Australia, heavy storms and flooding are expected to become more common due to extreme temperature fluctuations Recent data shows a significant rise in flood events over the past two decades, with the eastern regions becoming drier and the western areas experiencing more intense rainfall The increasing number of extreme hot days further underscores the urgent need for infrastructure resilience, as road networks face heightened risks from storms and flooding in the near future.
Table 1.1 Statistics of flood events
Time period Number of flood events
Rising sea levels, driven by global warming, increase the risk of flooding, tsunamis, rainstorms, and high tide events threatening coastal cities Since 1990, sea levels have risen by 20-60cm, with projections indicating continuous increases (Guha-Sapir & Hoyois, 2014) This escalation leads to inundation of coastal fringe areas and makes infrastructure such as buildings and roads more vulnerable Additionally, the reduction in straight-line distances between coastal cities and the shoreline heightens the impact of ocean-related disasters.
Distribution of cities and flood events
In Australia, the majority of the cities and populations located around coastal lines According to the population distribution research, the majority of Australians live within 50
Coastal kilometers (Hugo 2003) highlight the extensive reach of shoreline areas, while high population density regions typically have more developed road infrastructure and support facilities (Figure 1.4) These transportation networks are highly vulnerable to extreme coastal weather events, with roadway and bridge infrastructure frequently impacted during floods According to the Bureau of Meteorology (BOM) Australia 2011, dynamic river flood maps closely align with the distribution of road networks, demonstrating how flood events have historically caused significant damage to transportation infrastructure Bridges, integral components of road systems, are particularly exposed to flood risks, emphasizing the need for resilient infrastructure planning.
Figure 1.3 Cities distribution of Australia(ABS 2010a July 2011)
Figure 1.4 Distribution of road infrastructure (Jennifer Baxter March 2011)
Figure 1.5 Flood events distribution(Australia Government Bureau of Meteorology 2011)
In recent years, coastal areas have seen a surge in residents, primarily younger generations, increasing their vulnerability to flood events The growing population places greater demand on transportation infrastructure, leading to more extensive and dense road networks in these regions This expanded road infrastructure results in a higher number of bridges and critical structures exposed to the risks of extreme storms and flooding, heightening the overall vulnerability of coastal communities (Hugo, 2003; Bankoff, Frerks & Hilhorst).
Flood events in 2004 highlighted that recovery costs for damaged bridges are significantly higher due to increased labor expenses, the implementation of advanced technology, and the larger scale of construction required Additionally, the need for more overpasses and related facilities further contribute to elevated post-disaster recovery costs These factors collectively result in increased financial requirements for restoring infrastructure after flooding incidents.
Mitigation through disaster relocation is regarded as one of the most effective strategies to protect communities from frequent and predictable natural disasters, thereby reducing long-term recovery costs (Perry & Lindell, 1997) Various regions, including Darwin in 1979 and the United States through FEMA's programs, have attempted community relocations to mitigate disaster risk, though success remains limited In Japan, legislative support such as the Act on Special Financial Support promotes group relocations for disaster mitigation However, challenges such as high relocation costs and residents' attachment to their homes often impede successful evacuation efforts Historically, forced relocations, like Darwin's in 1979, faced resistance, but contemporary approaches emphasize voluntary relocation supported by governmental assistance (Matthews et al., 2002) For instance, residents in Lockyer Valley have repeatedly chosen to stay despite experiencing multiple severe floods, illustrating the importance of respecting personal willingness in disaster mitigation strategies.
Most residents in flood-prone regions tend to stay despite the risks, making evacuation challenging Maintaining access to critical infrastructure like bridges and roads is essential for community safety and recovery efforts in these vulnerable areas Currently, the Australian government lacks a comprehensive strategy to relocate large populations from disaster-prone zones, despite research from CRC Bushfire indicating that relocating residents could be more cost-effective than frequent rebuilding (Clint Jasper, 2015) However, implementing such relocations remains impractical, even if they prove economically beneficial in high disaster risk areas.
In the near future, climate change is expected to lead to more frequent and severe extreme weather events, resulting in increased flooding across Australia Additionally, the growing population in flood-prone regions will drive a higher demand for resilient infrastructure, particularly the construction and maintenance of bridges to enhance flood resilience and community safety.
Debris and deposition cleans up cost
Cost of traffic/transport disruption
Business interruption due to the loss of the road
Damage to cultural/asset heritage
Loss of confidence/ trust in Authorities
Loss of jobs (Social disruptions)
Community disorder and inadequate road infrastructure pose significant risks to bridge infrastructure, especially if the majority of the population is not effectively relocated Two key trends highlight these dangers: the increasing likelihood of future bridge damage due to flooding and the rise in traffic problems faced by residents when bridges are compromised Consequently, these issues are expected to lead to greater losses and disruptions in the future, emphasizing the urgent need for improved infrastructure resilience and population management.
The impacts of road infrastructure destruction on the local community in natural
The Cooperative Research Centre (CRC) highlights the significant economic losses caused by infrastructure damage during natural disasters, emphasizing the importance of understanding their impact on local communities (Jane Mullett, 2015) These economic effects can be categorized into four key aspects: direct tangible, direct intangible, indirect tangible, and indirect intangible implications, as summarized in Figure 1.6 Most research in this field agrees that the economic impact of natural disasters includes both measurable and less tangible effects, encompassing immediate damages and longer-term consequences (Hallegatte & Przyluski, 2010; McKenzie, Prasad & Kaloumaira, 2005).
Figure 1.6 The losses caused by road infrastructure destruction(Jane Mullett 2015)
Road infrastructure damage from natural disasters has far-reaching economic impacts on local communities, affecting long-term development and economic stability Identifying and verifying these impacts is essential, as more specific categories enable accurate calculation of economic losses (McKenzie, Prasad & Kaloumaira, 2005) Reviewing existing research and interviewing affected individuals help create a comprehensive impact matrix (Figure 1.6), which categorizes economic effects by different characteristics to prevent double counting in disaster assessments (Gentle, Kierce & Nitz, 2001).
This CRC research explores the economic impacts of bridge damage during flood events, highlighting the vital role of bridges as key components of road infrastructure Damaged bridges can significantly disrupt local communities, leading to economic losses and infrastructural challenges Identifying and summarizing these economic impacts is essential to understanding the broader consequences of flood-related bridge damage and developing effective mitigation strategies.
Bridge damage in flood events
Bridges are essential components of road networks, designed to withstand flood events based on available construction practices Damage to bridges during floods can disconnect road networks on either side of a river, leading to immediate and prolonged disruptions to social connections, business activities, and community interactions These disruptions result in significant economic losses, which accumulate over time until the bridges are repaired or restored (Negi et al., 2013).
Often, After a flood, there are two forms of damage, which can affect the bridge functioning and disrupt traffic:
(1) Debris: the accumulation of debris on the bridge interrupts traffic In some cases, the bridge structures have not been destroyed in flood events In fact, the reliability and stability
12 of the bridge are adequate for transporting vehicles However, the transportation flow is interrupted due to the debris built up on the bridge
Flood events can cause significant damage to bridge structural elements, compromising their stability and reliability It is essential to conduct thorough inspections of the bridge’s structural components immediately after a flood Following the inspection, necessary repairs or replacements should be carried out to ensure the safety and integrity of the bridge Proper maintenance and prompt response are crucial for minimizing infrastructure risks and preventing potential failures.
During flood events, a bridge's condition can either remain intact or be completely destroyed, significantly impacting its accessibility and functionality Debris accumulation and physical damage to the bridge structure often lead to disruptions in its operation The functional impact of a flood on a bridge typically occurs in three stages, as illustrated in Figure 1.7, highlighting the gradual decline and potential recovery phases of the bridge's integrity.
Figure 1.7 The bridge function change during and after flood events
The initial stage of flood impact on bridges involves damage and debris accumulation, with the duration lasting from a few hours to several days or even over a month During this phase, the functionality of the bridge diminishes progressively until the flood subsides This stage is critical in determining the post-flood accessibility and availability of the bridge, as core damages and debris obstructing the structure directly affect its usability (Przyluski & Hallegatte, 2011).
The response stage occurs after a bridge is damaged, during which it may be closed to ensure safety while inspections and repairs are conducted Key features of this phase include maintaining the bridge's condition from the initial stage, with no additional direct damage, and facing primarily indirect economic losses due to restricted access and reduced availability During this period, local governments and communities initiate rehabilitation efforts, including inspection and recovery activities When a bridge is closed or partially open, authorities implement traffic management strategies to mitigate adverse effects The speed and effectiveness of post-disaster response heavily depend on prior preparation, such as emergency plans, facilities, and materials, which can significantly reduce response time (Fiedrich, Gehbauer & Rickers, 2000) Adequate pre-disaster planning enables a faster and more efficient response to natural hazards.
The recovery stage involves the gradual restoration of the road’s functionality until it fully recovers from damage, with damaged bridges either returning to pre-disaster conditions or reaching a improved state through advanced technology and design When a damaged bridge regains its pre-disaster performance, negative effects are considered eliminated, often leading researchers to assume complete repair to original conditions The duration of recovery significantly impacts social, collective, and productive activities, as longer recovery times can result in greater indirect losses, affecting communities on both sides of the river.
Measure the economic impacts after flood events and the rationale of estimating
Measuring the economic impacts
Bridge disruption-related losses are categorized into tangible and intangible impacts While direct and indirect economic effects can be quantified using monetary methods, measuring intangible losses such as trust erosion and heritage value is more complex For instance, residents have expressed a loss of confidence in local government decisions following bridge disruptions (Jane Mullett, 2015) Accurately assessing these intangible losses is essential for comprehensive impact analysis and effective recovery planning.
After flood events, understanding the economic impacts of bridge disruptions is crucial for local councils and communities The costs can be categorized into three main aspects: direct costs such as the expenses for bridge recovery (Cho et al., 2001), indirect tangible losses resulting from restricted access caused by bridge damage, and the broader impacts on regional economic performance due to inconveniences faced by travelers and local businesses (Hopkins, Lumsden & Norton, 1993) These factors collectively affect the economic recovery and resilience of flood-affected areas.
The local council must consider several intangible economic impacts that could affect its governance and community standing Key concerns include the potential loss of authority and influence, psychological impacts on residents caused by bridge disruptions, and disruptions to the local labor market and community stability Addressing these issues is vital for maintaining effective governance and community cohesion.
The importance of estimating economic impacts of bridge damage
An accurate flood assessment report is essential for supporting effective rehabilitation and disaster preparedness, enabling local councils to identify vulnerable regions and prioritize resources It highlights weaknesses in road infrastructure, guiding improvements such as enhancing flood resistance of bridges, relocating roads, and providing alternative routes to mitigate future risks This assessment is crucial for pre-disaster planning, ensuring targeted strategies for recovery, especially for the most affected residents and industries Additionally, it allows councils to verify the capacity of alternative road networks and assess whether they can handle increased traffic after infrastructure damage, helping to manage travel times and reduce congestion during recovery periods.
Research questions and objectives
Research questions
There are 2 main research questions in this thesis:
1 What are the economic impacts of bridge damage in flood events? How to categorize these economic impacts systematically?
Researchers have attempted to apply methods or models to measure the economic losses after natural disasters The first step is to define impacts accurately In different studies, different
16 research purposes and scopes would lead to different category scopes The economic impacts had been included in various categories by different papers (Hughes 2003)
This study explores the crucial relationship between bridges and various economic sectors, highlighting that road infrastructure serves as the backbone for overall infrastructure development and economic activity Bridge collapses can disrupt surrounding road networks, leading to significant economic losses across social sectors The research aims to categorize the different types of economic impacts resulting from bridge damage, emphasizing the lack of existing studies on the economic consequences of bridge destruction during natural disasters To address this gap, the study will draw insights from previous research and expert interviews to identify and summarize these economic impacts effectively.
2 How can thees economic losses be measured?
To accurately assess the economic impacts of bridge damage caused by flood events, it is essential to categorize the types of losses and apply appropriate methods and models for estimation Various approaches exist to quantify the economic damages resulting from severe floods, yet many of these models lack comprehensive validation, as highlighted by Merz et al.
This research aims to identify effective methods for assessing the economic impacts of flood events on local communities, focusing on regional-level analysis It emphasizes evaluating both direct costs, such as repair or replacement of concrete bridges, and indirect costs affecting residents Additionally, the study highlights the importance of developing appropriate approaches to interpret intangible economic losses, which are challenging to quantify in monetary terms but significantly impact the community.
Research objectives
The economic impacts of bridge damage due to flood events on the local community have not been discussed and analysed systematically Therefore, this research will focus on four aspects:
(1) Identifying the economic impacts of bridge damage in flood events on the local council/community
(2) Categorizing the economic impacts systematically, dividing them into direct and indirect and tangible and intangible
(3) Introducing proper models to measure the tangible losses and interpret the intangible losses accurately
(4) Demonstrating the integrating model in case study
Research significance
Road networks are essential lifeline systems that support the construction, maintenance, and repair of other critical infrastructure (Hopkins, Lumsden & Norton, 1993) Developed economies heavily depend on transportation systems to ensure economic stability and growth (Dalziell & Nicholson, 2001) Flood events that destroy roads can have severe consequences, especially when it comes to bridges, which represent a significant investment with high construction costs and substantial economic value (Xie & Levinson, 2011) Damage or collapse of bridges disrupts connectivity and accessibility across rivers, affecting social, business, and community activities As such, bridges significantly impact stakeholders relying on their use, making it vital for local communities to estimate potential costs and economic output during bridge recovery efforts.
The local community requires an accessible method to evaluate the economic impacts on their economy and overall well-being It is essential for the local council to have comprehensive data regarding the economic consequences of bridge damage during the rehabilitation process Conducting accurate estimations of these impacts provides significant benefits, such as informed decision-making and effective planning to minimize disruptions, ultimately supporting the community's economic stability and resilience.
(1) Estimation can point out which area would be more vulnerable and suffer the most loss during bridge recovery
(2) The targeted strategy could be made to support most vulnerable areas to overcome traffic and transportation problems
(3) Estimation could help the local community to plan and verify before/post disaster preparation, disaster mitigation solutions, and reconstruction process to relieve damage in different areas
(4) Estimation could be evidence to plan recovery and improve recovery efficiency.
Outline of the thesis
This thesis has seven main chapters Each chapter would include one theme that would relate to research topics:
Chapter 1 outlines the key reasons guiding this investigation, emphasizing the critical importance of bridges for infrastructure and transportation It highlights the threats posed by natural hazards, such as floods, which can cause significant damage to bridge structures The chapter also addresses future challenges related to increasing flood events due to climate change Additionally, it defines the primary research topics and questions aimed at assessing and mitigating flood risks to ensure bridge safety and resilience.
Chapter 2 provides a comprehensive overview of the current understanding of the economic impacts of bridge damage during flood events It highlights the significance of evaluating infrastructure vulnerabilities and their effect on regional economies The chapter also reviews existing concepts and models used to quantify economic losses, emphasizing their importance in developing effective mitigation and response strategies Accurate measurement of flood-related bridge damages is essential for informed decision-making and infrastructure resilience planning.
Chapter 3 describes the research methodology in detail including the research plan, data collection methods, research instrument, type of data to be collected, and data analysis
Chapter 4 provides a comprehensive overview of the economic impacts resulting from bridge damage during flood events, drawing on previous research It highlights the various ways in which bridge failures can affect local and regional economies, including costs related to infrastructure repair, transportation disruptions, and economic losses The chapter utilizes a causes and effects analysis to categorize different types of economic impacts, emphasizing how flood-induced bridge damage can lead to significant financial burdens and long-term economic consequences This analysis underscores the importance of understanding and mitigating the economic risks associated with bridge vulnerabilities during floods.
Chapter 5 leverages current concepts and models, such as performance groups and damage states, to effectively assess and quantify the economic impacts identified in Chapter 4 Key focus areas include analyzing detouring costs for bridge users and evaluating the extent of business interruption, providing a comprehensive understanding of the economic consequences These advanced modeling approaches enable precise measurement of economic impacts, supporting informed decision-making and effective infrastructure management.
Chapter 6 uses the Kapernicks Bridge, which is located in Lockyer Valley region, Queensland, to illustrate the integrating model It will also discuss current limits to apply the integrated models
Chapter 7 offers conclusions regarding research objectives, contributions to current knowledge, implications to investigations and recommendations for further research
Natural disasters and disaster impact
Classification of the economic impacts
Most current economic studies utilize similar classification methods, adjusting definitions and scopes of each impact type based on their research objectives This research compares two mainstream classification approaches, highlighting their differences and applications within economic impact analysis.
Mainstream categorization methods differentiate between direct and indirect losses caused by disasters Direct impacts refer to damages resulting immediately from the disaster event, while indirect impacts are the secondary ripple effects that occur subsequently, not caused directly by the disaster itself Understanding this distinction is crucial for comprehensive disaster loss assessment and resilience planning.
Research on disaster impacts varies across 23 different categories, primarily due to differing research purposes and scopes For instance, business interruption is categorized separately into direct, indirect, or other specific types depending on the focus of each study This variation reflects how researchers tailor their classifications to align with their unique objectives and methodologies (Hallegatte & Przyluski, 2010).
Research distinguishes between tangible and intangible economic losses, based on whether they can be measured by monetary flow Tangible costs refer to objects with a clear market value or resource flows, such as damaged assets, making them easily quantifiable in monetary terms In contrast, intangible costs lack market value or are difficult to assign a monetary value, including critical factors like loss of lives Understanding this distinction is essential for comprehensive economic loss assessment in research.
In Costs of Natural Hazards Research (CONHAZ), economic impacts are classified into five key categories: direct costs, business interruption, indirect costs, intangible costs, and risks mitigation costs, providing a comprehensive framework for assessing the economic effects of natural hazards.
CONHAZ's second classification method is unsuitable for this research due to the complexity of applying its concepts, particularly business interruption and mitigation costs Business disruption caused by floods encompasses both direct damages to property and indirect effects such as disruptions in power, water, internet, and transportation, making it challenging to distinguish between them; in this study, business disruption is considered an indirect loss stemming from transportation problems caused by bridge damage Additionally, defining mitigation costs is problematic, as certain investments, like steel bracing projects implemented post-flood, serve dual roles as both mitigation for future events and part of immediate repair expenses, complicating their classification and analysis.
The first classification system is more suitable for this research, as it logically categorizes the economic impacts into four key aspects: direct impacts, secondary impacts, market value, and non-market value This approach provides a comprehensive understanding of how economic effects manifest and their respective significance within the study Utilizing this classification enhances clarity and aligns with best practices for analyzing economic impacts in research.
Economic impacts of road infrastructure disruption in natural disasters
Flood events have diverse impacts across society, with research primarily analyzing the economic effects on six key social sectors: private households, industry and manufacturing, the services sector, the public sector, lifelines and infrastructure, and agriculture Studies also examine critical aspects such as evacuation, disaster mitigation, post-disaster recovery, and disaster management Most research focuses on one or two aspects, revealing that economic impacts vary due to researchers' knowledge and experience, as well as differing research objectives and scopes Enhanced cooperation and coordination are essential for a comprehensive understanding of flood-related economic impacts across sectors.
The Cooperative Research Centre (Setunge et al., 2015) in Australia conducted collaborative research to understand community resilience in the face of road network disruptions, building on earlier efforts in this field As early as 1993, researchers like Hopkins, Lumsden, and Norton highlighted that road infrastructure is vital, as it connects and supports other sectors and society as a whole Most studies focus on the reliability, performance, and recovery of road networks following natural disasters (Chang & Nojima, 2001; Karlaftis et al., 2007; Sakakibara et al., 2004; Sumalee & Kurauchi, 2006), while others examine the economic impacts and performance of road infrastructure under natural hazard conditions (Cho et al., 2001; Xie & Levinson, 2011).
25 the understanding of road infrastructure and its important role in the local community in a natural disaster is still limited
Research on CRC examines the impact of four main natural hazards—floods, earthquakes, bushfires, and climate change—on road infrastructure in Australia The initial phase involved reviewing previous studies and interviewing disaster victims to understand the extent of damage A comprehensive matrix has been created to quantify the economic impacts of road infrastructure disruptions caused by these natural disasters, as detailed in Figure 2.1 (Jane Mullett, 2015; Setunge et al., 2015).
Figure 2.1 Economic impacts of road infrastructure damage
Significance of bridges in road infrastructure
As a significant part of road infrastructure, bridges have a special status in road infrastructure
Bridges serve as crucial connectors between two separate transportation systems across rivers or road networks, significantly enhancing overall connectivity While they offer substantial benefits, bridges can also impact other social sectors and influence the performance of surrounding road networks In some extreme cases, these structural changes may lead to increased traffic congestion or infrastructural challenges, highlighting the importance of careful planning and integration within urban transportation systems (Dalziell & Nicholson, 2001).
Debris and deposition cleans up cost
Cost of traffic/transport disruption
Business interruption due to the loss of the road
Damage to cultural/asset heritage
Loss of confidence/ trust in Authorities
Loss of jobs (Social disruptions)
26 bridge is the most important connection with the outside world The Vanuatu earthquake in
2002 led to the collapse of a bridge As a consequence, the local government had to use boats and helicopters to transport food and shelter to the local community (McKenzie, Prasad & Kaloumaira 2005)
A bridge's special value lies in its considerable construction importance, as repairing or rebuilding a damaged structure demands substantial financial investment According to the Lockyer Valley report, addressing the aftermath of the devastating January flood highlights the significant costs associated with restoring vital infrastructure like bridges.
In 2011, nearly all of Lockyer Valley’s 48 bridges required repairs or replacements, with costs amounting to $11 million, highlighting the extensive infrastructure damage (Queensland Reconstruction Authority, 2015) Bridges play a crucial role in supporting the local economy, and closing them can lead to significant economic and social consequences, as their disruption causes substantial indirect losses (Hallegatte & Przyluski, 2010; Seifert et al., 2010) According to Petrucci (2012), bridge collapses represent some of the most severe damages to regional communities, emphasizing the importance of maintaining these vital assets Moreover, bridges are essential infrastructure facilitating rapid economic recovery after disasters, underscoring their critical value for regional resilience (Kreimer, Arnold & Carlin, 2003).
Bridges play a crucial role in driving economic growth and can indirectly influence other sectors through their impact on surrounding road networks Understanding the economic consequences of bridge damage requires a precise analysis of the causes and effects involved Effective assessment of bridge-related disruptions is essential for minimizing economic losses and ensuring the stability of related infrastructure.
Bridge damages and access
Debris and debris clearance after flood events
The debris which is defined as the waste created by disasters (Çelik, Ergun & Keskinocak
Debris flow and debris removal significantly impact the accessibility of road infrastructure, often leading to bridge closures and traffic congestion, which require substantial disaster rehabilitation efforts Studies, such as Kreibich (2009), highlight that debris cleaning can account for up to 27% of total disaster-related losses (FEMA, 2007) To mitigate these effects, decision support models like the POMDP have been developed to optimize debris cleaning and disposal, aiding local governments in response efforts (Fetter & Falasca, 2011) However, most research focuses on rapid debris removal rather than accurate estimation of debris quantities generated during catastrophes, such as the Haiti earthquake (Booth, 2010) Currently, debris quantity estimation primarily relies on surveys and observations, exposing a knowledge gap in predicting debris generation based on regional parameters during flooding events, emphasizing the need for improved predictive models.
Estimating debris quantities around a damaged bridge is more straightforward than assessing all flood-impacted areas due to the smaller affected zone and simpler debris composition This targeted approach requires fewer sampling points, making debris assessment faster and more efficient Accurate debris estimation around damaged infrastructure is essential for effective flood response and recovery planning.
Effective debris cleaning after disasters involves two key stages: debris collection and debris disposal (FEMA 2007) The debris collection process can be further divided into collection and transportation, emphasizing the importance of efficiently moving debris from affected areas to designated disposal sites (Ghose, Dikshit & Sharma 2006) Managing these stages is crucial, as debris collection includes costs associated with gathering debris in disaster-affected regions and transporting it to properly designed dump sites, ensuring a streamlined cleanup process.
Australia has a government-guided waste disposal system emphasizing proper debris treatment to reduce environmental impact Waste is categorized into general waste and green waste, with additional subcategories such as dry or wet, solid or liquid waste Recycling is a common method for suitable debris, while others are disposed of through burning or burial The primary waste disposal techniques in Australia are recycling and landfill, with costs varying across different states and waste types (Productivity Commission, 2006) Proper waste management practices are essential for minimizing environmental harm and promoting sustainability.
Best Control (AUD) Poor Control (AUD)
During bridge repairs in Australia, managing construction waste is essential, with government guidelines recommending recycling to minimize environmental impact Recycling construction waste helps conserve land and reduces pollution by diverting debris from landfills Additionally, recycling materials preserves natural resources and supports environmental sustainability Australian states implement gate fees for waste recycling services, covering costs such as collection, transportation, and disposal of debris and construction waste This approach promotes environmentally responsible waste management during infrastructure repair projects.
Bridge structural damage after floods
502 Bad GatewayUnable to reach the origin service The service may be down or it may not be responding to traffic from cloudflared
502 Bad GatewayUnable to reach the origin service The service may be down or it may not be responding to traffic from cloudflared
502 Bad GatewayUnable to reach the origin service The service may be down or it may not be responding to traffic from cloudflared
Table 2.2 Damage Grade of QLD Road Inspection
Condition state Subjective rating Description
2 Fair Free of defects affecting structure performance, integrity and durability
Defects affecting the durability which require monitoring, detailed structural engineering inspection or maintenance
Defects affecting the performance and structural integrity of the structure which require urgent action as determined by a detailed structural engineering inspection
5 Unsafe Bridge must be closed
502 Bad GatewayUnable to reach the origin service The service may be down or it may not be responding to traffic from cloudflared
Figure 2.2 Damage states that are used by CONHAZ (Merz et al 2010)
Besides, this method also consider water resistence of different construction material The flood resistance of different materials is shown in figure 2.3(Figure 2.3) (Schwarz & Maiwald
This method categorizes various road infrastructure performances based on construction materials during flood events, highlighting how building design and material choices are crucial for accurately assessing and predicting damage under similar flood conditions By analyzing different construction materials, the approach enables the calculation of damage ratios to forecast the structural integrity of bridges after floods Additionally, the identification of vulnerable ranges for buildings constructed with different materials (as outlined in Table 2.3) enhances the precision of flood damage assessments and supports resilient infrastructure planning.
In assessing bridge damage during flood events, it is essential to consider different design and construction materials separately, as each material responds uniquely to flooding To accurately evaluate the average damage condition and identify characteristic deterioration patterns, bridges should be grouped based on their shared design and material characteristics This approach allows for a more precise understanding of damage traits and improves the reliability of damage assessments in flood-prone scenarios.
Flood vulnerability class (High to low)
Most likely vulnerability class Probable range
Range of less probable, exceptional cases
HAZUS employs a specific damage state method to assess bridge damage following disaster events, using five distinct damage levels to categorize varying degrees of destruction This standardized approach, utilized by the Federal Emergency Management Agency (FEMA), facilitates accurate estimation of repair and replacement costs (Merz et al., 2010).
Table 2.4 Damage states by HAZUS
The structure exhibits minor cracking and spalling in the abutments, with cracks observed in the shear keys at abutments Additionally, there is minor spalling and cracking at the hinges and slight spalling at the columns, which require only cosmetic repairs The deck shows minor cracking, and the operator house has minor damage, all of which do not impact structural integrity.
Columns showing moderate shear cracks and spalling may still be structurally sound, but require careful inspection Moderate movement of abutments (less than 2 inches), extensive cracking and spalling of shear keys, and damage to connections such as cracked shear keys or bent bolts can compromise bridge safety Failure of keeper bars without unseating, rocker bearing issues, and moderate settlement of the approach indicate potential structural concerns Additional signs include moderate scour of abutments or approaches, damaged guardrails, and wind or water damage to operator houses that may result in switchboard or content damage, all requiring prompt assessment and repair.
Structural issues such as shear failure indicating column instability, significant residual movement at connections, and major settlement approaching critical levels compromise safety Additional concerns include vertical offset of abutments, differential settlement at connection points, shear key failure at abutments, and extensive scour compromising foundation stability Submerged electrical or mechanical equipment damage further heightens the risk of structural failure, emphasizing the need for thorough inspection and maintenance to ensure safety and integrity.
Any column collapsing or connection losing all bearing support, which may lead to imminent deck collapse, tilting of substructure due to foundation failure
This approach emphasizes assessing the extent of damage across various structural components following disaster events to ensure accurate evaluation of bridge safety It estimates the overall reliability and stability of bridges by analyzing individual structural elements, providing a comprehensive understanding of potential vulnerabilities The method incorporates the concept of performance groups, which categorize discrete damage states within different components, recognizing their interconnected roles in load transfer By evaluating these performance groups, the model facilitates coordinated repair strategies, ensuring that related structural elements are addressed together to restore bridge integrity effectively.
Estimating repair costs is enhanced through the use of performance groups, enabling more accurate and meaningful assessments By determining the quantities for each performance group, the total repair costs across all groups can be effectively calculated This approach allows for independent decision-making and estimations for each performance group, leading to better resource allocation and cost management in maintenance planning.
Figure 2.3 Use performance groups to estimate repair costs
The third inspection method offers clear advantages over the other two, primarily because it has been validated through estimated bridge repair costs, making it highly reliable for assessing damage While the first method focuses on bridge strength and safety for initial inspections, it does not provide detailed damage assessments once a bridge is deemed unsafe The second method estimates property losses in flood-affected regions, including bridges, but lacks the precision needed for individual bridge evaluations In contrast, the third method is specifically designed to accurately describe the damage state of a single bridge and comprehensively estimate repair costs, making it the most suitable choice for detailed damage assessment and cost estimation.
35 of single bridge damages By setting performance groups, a more meaningful assessment of bridge damage, bridge strength, and bridge repair costs could be performed
Different bridge types exhibit distinct damage states and performance groups, with damage descriptions varying among timber, concrete, and steel structures For concrete bridges, damage assessments focus on issues such as cracks and spalling, while steel bridges primarily involve deformation and fatigue-related damage Research by Mackie, Kevin R., Wong, and Stojadinović in 2010 classified various damage levels of concrete bridges, providing a detailed framework for assessment (Mackie, Kevin R., Wong & Stojadinović, 2010) However, there is a lack of standardized descriptions and detailed criteria for damage levels in timber and concrete bridges This study aims to address these gaps by introducing comprehensive damage states and performance groups specifically for concrete bridges based on current knowledge limitations.
Model review
Bridge repair costs
This research focuses on bridges and the damage they sustain during flood events, highlighting the various types of losses resulting from bridge failures Unlike studies that examine the direct impacts of natural disasters, this study emphasizes the specific consequences of flood-induced bridge damage Understanding how floods affect bridge infrastructure is crucial for developing resilient transportation networks and minimizing economic and safety risks associated with such events.
The definition of direct costs varies across different models and research studies, with some describing direct losses as stock loss, including repair and replacement costs after disasters (Fujimi & Tatano, 2012) Mainstream disaster research institutes typically define direct costs as expenses directly resulting from disaster events, though the specific categories depend on research objectives For instance, in CONHAZ flood reports, the disruption of production—such as workplaces being inaccessible—is considered a direct effect or direct cost (Bubeck & Kreibich, 2011b; Queensland, 2002) Conversely, CRC Australia’s research on the economic impact of road infrastructure classifies the inability to access workplaces as an indirect cost, focusing solely on direct costs like bridge recovery and debris clearance, excluding vehicle damages on bridges.
There is ongoing controversy surrounding the measurement of bridge repair costs, primarily related to the methods used for cost evaluation The two main approaches are replacement cost and depreciated cost of damaged assets Replacement cost assumes that damaged goods and services will be entirely replaced with new ones of equal value, which can lead to overestimating losses because this method does not accurately reflect the actual condition of the assets Consequently, relying solely on full replacement cost may overstate the true costs of repair and recovery.
Approximately 37% of the assets have been depreciated due to damage In some cases, reconstructed bridges may improve beyond their pre-disaster condition, offering enhanced durability and functionality Flood events can lead to improvements in repaired and reconstructed structures, resulting in better overall infrastructure resilience (Penning-Rowsell, EC & Wilson).
There is often a shortage of using full replacement costs in asset valuation, as this method assumes damaged assets will be fully replaced with new ones, potentially leading to overstated estimates In some cases, replacement costs can even be cheaper than repairing goods to their original condition (Merz et al., 2010) Most valuation models prefer using replacement costs over depreciation, since depreciation must account for each asset's specific condition and life cycle.
When assessing bridge damage, both replacement cost and depreciated cost aim to reflect the full value of replacing the entire structure However, in practical scenarios, repairing a damaged bridge is often more cost-effective than full replacement, making repair costs generally lower than the full replacement cost To ensure accuracy, it is essential to estimate repair or replacement costs based on the specific damage conditions, including the extent of damage, repair methods, construction materials, and the size of the affected structures Aligning repair assessments with these factors leads to more precise and reliable cost evaluations.
Table 2.5 Estimate the direct damage that is caused by flood events
Estimation direct costs of bridge damage in flood events
Loss determining parameters Data needs
Model of multi-coloured manual
Residential and commercial properties, leisure and sports facilities, public buildings, infrastructure
Water depth, flood duration, building/object type, building age, social class of the occupants, warning time
Values of exposed assets, socio- economic information, hazard characteristic
Seifert et al 2010; Thieken et al 2008)
Residential buildings, public and private services, producing industry, corporate services, trade
Water depth, contamination, building types, quality of building, precaution, business sector, number of employees
Values of exposed assets, residential buildings and company characteristic, hazard characteristic
Residential and commercial properties, infrastructure
Water depth, object size economic sector, object susceptibility
(Sturgess 2000) Australia Absolute Empirical synthetic
Object size, object value, lead time, flood experience
Object characteristics, land use, warning times, flood experiences, season Model of MURL
Land use data, values of exposed assets, water depth
Residential buildings, commerce, vehicles, agriculture, forestry, infrastructure
Land use data, values of exposed assets, water depth
Residential buildings, commerce, infrastructure, agriculture, vehicles
Water depth, flow velocity, wave action object type, riverine or coastal flooding
Object type, land use data, hazard characteristics
(Fửrster et al 2008) Germany Relative Empirical synthetic Agriculture Flood duration, crop types, season
Market prices of agricultural goods, planted crop types, flood characteristics
Residential and commercial properties, agriculture, infrastructure, nature recreation, vehicles
Flood depth, flow velocity economic sector
Values of exposed assets, socio- economic data, land use, hazards characteristics
(Maiwald & Schwarz 2010) Germany Relative Synthetic Residential properties
Water depth, flow velocity, structural characteristic
Information on building structure, land use data, hazard characteristics
Values of exposed assets, information on building structure, hazard characteristics
Flood disaster models typically incorporate parameters such as inundation depth, velocity, duration, contamination, debris, sediments, and the rate of rising water to accurately assess damage (Kato & Torii, 2002; Kreibich et al., 2009; Thieken et al., 2008) Some models also consider building resilience factors, including building type, materials, precautionary measures, external emergency responses, and early warning systems to evaluate flood impacts (Penning-Rowsell et al., 2005; Penning-Rowsell & Wilson, 2006; Schwarz & Maiwald, 2008) These parameters are effective when estimating average regional damage to infrastructure like bridges; however, damage prediction at the individual bridge level primarily focuses on force analysis and potential damage, which introduces significant uncertainties and biases An analysis of 4,000 damage records revealed that damage models often lead to under or overestimation, highlighting the challenges in precise flood damage prediction for single structures (Merz et al.).
2004) In this research, these models are hard to apply due to problems of accuracy However, they pointed out ways to measure bridge damage accurately
This article discusses flood damage modeling approaches, emphasizing that empirical models rely on historical data and detailed post-disaster surveys to estimate structural damages, making them suitable for individual bridges at this stage Conversely, synthetic models use expert-defined parameters to evaluate damage levels, offering alternative estimates Both methods are based on analyzing damaged objects and inherently involve uncertainties that can influence damage assessments and repair costs after floods Overall, empirical approaches tend to provide more detailed damage information for specific structures like bridges, while both models are essential tools in flood risk analysis.
There are two primary methods for measuring monetary losses from direct bridge damages: absolute damage and relative damage Absolute damage estimates align the cost of damaged structural elements with monetary values based on flood impact assessments (Messner, 2007), while relative damage links the damaged components to a proportion of the building’s maximum asset value (Bubeck & Kreibich, 2011a; Messner, 2007) In Australia, direct cost models mainly rely on absolute damage assessments, exemplified by the Anuflood and RAM models developed in Queensland and Victoria, which also address indirect flood-related losses These models estimate indirect costs such as business interruption, public service disruption, and cleanup as fixed ratios of direct damages; however, their results on indirect losses are often incomplete and lack accuracy.
This research confirms that absolute damage remains a reliable method for describing bridge damage accurately Absolute damage assessment provides more detailed and precise evaluations of a single bridge's condition compared to parameter-based alignment methods, which may risk underestimating or overestimating damage According to Kevin R et al (2007), combining inspection data with damage quantification yields more accurate estimates of repair costs and recovery time Additionally, performance groups are utilized to assist in calculating repair costs following inspections, enhancing the accuracy of damage assessment and repair planning.
Value of historical bridge
Some bridges are considered heritage assets due to their unique cultural significance, encompassing aesthetic, historical, scientific, social, or spiritual values for past, present, and future generations (The Allen Consulting Group, 2005) These heritage bridges possess non-market values that go beyond their physical assets To quantify the intangible worth of historic bridges, methods such as surveys measuring willingness to pay (WTP) and willingness to accept compensation are commonly used (Mitchell & Carson, 1989) The total economic value is calculated by multiplying the average WTP by the regional population, providing a comprehensive assessment of their cultural and social importance.
Advancements in economic theory and social survey methodology have led to the development of more accurate methods for estimating economic impacts that lack explicit market values Several of these innovative approaches can be reviewed to improve assessment accuracy, ensuring comprehensive evaluation of non-market economic contributions.
Table 2.6 Intangible values of heritage buildings
(Bedate, Herrero & Sanz 2004; Choi et al 2010;
(Brown Jr & Mendelsohn 1984; Choi et al 2010; Poor
Maintenance cost method (Poor & Smith 2004;
Husain 2007; Lee & Han 2002; Tuan & Navrud
(Choi et al 2010; Morrison, Bennett & Blamey 1999; Tuan & Navrud 2007)
In 2005, the Heritage Chairs and Officials of Australia and New Zealand conducted research to assess the value of heritage conservation across Australia, reviewing various literature, methods, and standards to identify strengths and challenges (Ruijgrok, 2006; The Allen Consulting Group, 2005) This initiative included evaluations of the heritage significance of historical buildings nationwide, with surveys and standards established to guide conservation efforts While comprehensive surveys were part of the broader assessment, this particular research focuses on obtaining heritage value evaluations specifically when heritage buildings sustain damage, relying on insights from the Heritage Chairs and Officials of Australia and New Zealand.
To accurately estimate the value of a historical bridge, it is essential to highlight its unique characteristics and what makes it distinctive The bridge's heritage significance largely stems from its humanistic value, historical importance, and architectural design Emphasizing these aspects helps in understanding its cultural and historical importance, contributing to comprehensive valuation and preservation efforts.
(Navrud & Ready 2002) In this circumstance, comments about the bridge should include a short summary of cultural humanistic value, history, and designing.
Indirect cost
This research concentrates on the indirect economic impacts resulting specifically from bridge collapses following flood events, differentiating from broader impacts caused by natural disasters While many studies define indirect impacts as including all secondary consequences of disasters (Rose, 2004), this study emphasizes losses related to changes in access, such as increased travel distance and time, delays in recovery, and disruptions to input and output activities due to bridge damage Unlike general indirect impacts from floods, the focus here is on economic losses stemming from impaired transportation infrastructure.
Common methods for measuring indirect economic losses include firm and household surveys, input-output models to analyze sector interactions, and Computable General Equilibrium (CGE) models that assess market and price changes These approaches aim to identify specific relationships and mechanisms within the economic system to estimate potential indirect impacts Specifically, road infrastructure disruptions, such as bridge damage, primarily result in reduced accessibility, adversely affecting residents and local businesses.
Assessment approaches in economic analysis primarily rely on three model types: input-output (I-O) models, computable general equilibrium (CGE) models, and hybrid models I-O models are designed to estimate the impacts of one economic sector on others, operating under the assumption of fixed input-output relationships These models presume that inventories—such as technology, labor, materials, and production conditions—are non-substitutable, providing a straightforward framework to analyze sectoral interdependencies in the economy.
A lack of input ultimately impacts output, as a shortage in the model can lead to overestimating economic losses due to limited market flexibility and production constraints Rose (2004) critiques Input-Output (I-O) models for their inflexibility caused by fixed coefficients, their static nature, and their focus on equilibrium, which limits their ability to reflect dynamic economic changes Additionally, the model fails to account for the interactions between consumers, lost wages, profit incomes, and reduced employment, thereby oversimplifying complex economic relationships.
CGE models analyze market and price fluctuations following disasters by leveraging supply and demand relationships among households, businesses, and government institutions They model the interactions of goods and services to predict impacts on regional economic performance, offering flexibility and substitution options However, these models assume markets will operate perfectly post-disaster—an idealization that rarely reflects reality—potentially leading to conservative estimates and challenges in practical application.
The Hybrid model combines features of Input-Output (IO) and Computable General Equilibrium (CGE) models to enhance their effectiveness in assessing economic impacts It improves flexibility by introducing factors that modify substitution elasticity in CGE models or enhance the adaptability of IO models These advanced models represent an improvement over traditional IO and CGE frameworks, emphasizing the use of multiple relationships to accurately analyze economic repercussions following disaster events.
All models are limited by the availability of detailed and reliable data, which is essential for accurate estimations (Merz et al., 2010) Larger disasters tend to have more significant indirect effects, making comprehensive data collection from various social sectors even more critical (Hallegatte, 2008) In major crises, resources primarily focus on relief and recovery efforts, which complicates the collection of consistent and detailed records, especially when data is gathered from multiple institutions.
(1) Event analysis is based on survey It is good to collect information about losses after disasters However, it is difficult to explain business losses due to transport inconvenience
Econometric approaches, Computable General Equilibrium (CGE) analysis, intermediate models, and public finance analysis primarily focus on assessing the overall impact on the local economy and financial systems However, accurately measuring the economic effects generated by a single infrastructure project, such as a bridge, remains challenging due to the complexity of these models and the difficulty in isolating specific contributions.
General Method Specific Method Application examples
Surveys at firm level (Boarnet 1996)
(Tierney 1997) Surveys at household level
Gross regional domestic product effect assessment
National Gross domestic product effect assessment
Input-Output analysis Input-Output Models
(Hallegatte 2008) HAZUS-E (McCarty & Smith 2005) (Haimes et al 2005)
(Berrittella et al 2007) (Boyd & Ibarrarán 2009) (Horridge, Madden & Wittwer 2005) (Wittwer & Griffith 2010)
Hybrid Input- output/Computable General Equilibrium Models
Analysis of the impact on public finance
Modeling interactions of hazard impacts with technical change or business cycles
The idealized input-output model is a form of analysis that considers transportation as a crucial factor impacting a business’s productive capacity This model assumes that companies and industries depend on adequate stocks of essential resources such as materials, gas, power supply, and workforce to sustain normal operations Since these productive factors rely heavily on road infrastructure, disruptions in transportation—such as those affecting bridges—can be used to estimate reductions in overall productive capacity.
Loss of the accessibility
Measuring the value of bridge accessibility is crucial, especially during bridge clearance and repairs that can cause complete closures or partial openings, leading to detours and traffic delays These disruptions result in economic losses quantified by increased travel distance and time A relevant case study on the 58 Highway highlights how extra travel distance and time serve as indicators of these losses (Negi et al., 2013) Estimating these impacts requires data on detour routes, alternative road ratios, and average daily traffic (ADT) Additionally, regional vehicle operating costs can help accurately assess the detour costs for different vehicle types, providing a comprehensive understanding of the economic impact of reduced bridge accessibility.
To identify alternative routes and quantify additional travel distance and time, a GIS map can categorize various road types and measure travel metrics effectively GIS technology offers comprehensive solutions for building detailed maps tailored for research and analysis purposes This research utilizes the ArcGIS Road Information System, which incorporates data on different road types, post-disaster conditions, detour ratios, and local land use such as residents and farms, enabling precise analysis of road networks under various scenarios.
47 businesses, main services, daily destinations, etc would be summarized and reflected in regional maps
Regarding calculating extra traveling distance and extra traveling time, Google map provides a solution to estimating an ideal traveling time in ideal road conditions
2.3.4.2 Regional vehicle operating cost models
Vehicle operating costs are crucial in debris transportation and detours following natural hazards, encompassing fuel consumption, tire costs, maintenance and repair, oil use, and capital depreciation (Berthelot et al., 1996) Additional expenses such as licensing, insurance, and operator wages vary based on regional policies and salary levels However, most models tend to overlook factors like travel time savings and accident reduction (Thoresen & Roper, 1996) Historically, numerous studies on vehicle operating costs were conducted by various institutions toward the end of the 20th century (see Table 2.8) Notably, models like aaSIDRA (1984) were later enhanced in 2003 to estimate pollution and gas emissions, reflecting ongoing developments in transportation cost analysis (Akcelik & Besley).
Both the AUSTROAD (1994) and New Zealand (1989) models were developed to measure regional operating costs, with vehicle travel speed being a crucial factor in estimating fuel consumption across different models These models produce varying results depending on speed limits, highlighting the importance of accurate speed considerations The widely used HDM IV, developed by the World Bank, requires extensive supporting data for reliable estimation, making it data-intensive In contrast, the Canadian government's PVOC model offers a more streamlined approach with fewer parameters and supporting data, and it is unaffected by travel speed, making it easier to operate.
Table 2.8 Models of vehicle operating costs
Operating cost, fuel consumption, and emission models in aaSIDRA and aaMtion (Akcelik & Besley 2003)
HDM-IV application guide (Kerali, McMullen & Odoki
Review and enhancement of vehicle operating costs models: Assessment of non-urban evaluation models
Mechanistic-probabilistic vehicle operating cost models (Berthelot, CF et al 1996)
Road user cost determined from engineering first principles (Berthelot, C 1992)
The New Zealand vehicle operating cost model (Bennett 1989)
The PVOC model, developed by the Canadian government, is regarded as the most suitable framework for this research It comprehensively accounts for various cost factors, including fuel consumption, tire expenses, maintenance and repair costs, oil consumption, and capital depreciation, providing a holistic approach to cost analysis.
This model requires fewer data compared to other existing models, making data collection more straightforward It is easy to operate and does not require complex statistical analysis, with fewer parameters than other models, reducing potential data collection issues Additionally, most parameters can be adjusted using local vehicle data, resulting in more accurate outcomes that account for variations in vehicle constitution, road conditions, and user preferences.
Some other economic losses and estimation methods
There are some approaches which are developed to estimate the economic impacts of road infrastructure and bridge collapse could also be used to improve accuracy of this research:
Research on the Mississippi River bridge collapse indicates that 92% of residents would continue their daily trips, primarily adjusting departure times and schedules rather than canceling trips (Xie & Levinson, 2011) These findings demonstrate that most stakeholders are committed to maintaining their travel routines, with travelers rerouting through alternative roads, which diverts traffic flow and increases pressure on nearby routes The study also highlights that detour choices impact travel distance and time, leading to greater congestion on alternative pathways and a decrease in overall travel efficiency for the local community.
In 2009, Kevin Mackie, Wong, and Stojadinović developed a comprehensive model for estimating bridge repair costs and timeframes following earthquake damage This approach links repair costs and schedules to unit costs and repair quantities, providing valuable insights for post-disaster decision-making Using a reinforced concrete highway bridge as a detailed example, their assessment offers a clear recovery timeline and predicts the duration of economic impacts, aiding in disaster response planning The model also incorporates damage states, performance grouping, and inspection procedures, establishing a practical framework for estimating repair quantities and supporting efficient recovery strategies.
In their 2009 study, Padgett et al analyzed damage to bridge structural components caused by hurricanes, highlighting key differences between hurricane and earthquake damages They explored the correlation between damage severity and storm surge elevation, demonstrating that damage state assessment methods originally developed for earthquakes can be effectively adapted for hurricane-related infrastructure damage This research indicates that, despite different causes and stresses, damage assessment techniques have cross-disaster applicability, enhancing our understanding of bridge resilience under various extreme events.
50 similar (Padgett et al 2008) In this research, damage states methods could be based on these two damage states methods
In their 2001 research, Sungbin and Peter developed models including structure performance groups, transportation networks, spatial allocation, and inter-industry (input-output) models to analyze the relationship between transportation systems and urban economies Their study focused on assessing industrial capacity, transportation demand, and supply following an earthquake, offering insights into how infrastructure damage impacts economic resilience By integrating regional transportation networks, travel routines, and transportation demands, this research provided a comprehensive framework for estimating the economic impacts of bridge damage, demonstrating the importance of multi-sectoral modeling in urban disaster recovery analysis.
These models analyze key aspects of the economic impacts of bridge collapses, including damage severity, repair duration, travel demands, alternative routes, and business interruptions By integrating different research models, they provide valuable estimates of the specific economic consequences resulting from road infrastructure failures However, these studies also highlight significant limitations related to the current state of knowledge and challenges in data collection, which can affect the accuracy of impact assessments.