Life cycle analysis for sustainability assessment of road projects

Road infrastructure has been considered as one of the most expensive and extensive infrastructure assets of the built environment globally. This asset also impacts the natural environment significantly during different phases of life e.g. construction, use, maintenance and end-of-life. The growing emphasis for sustainable development to meet the needs of future generations requires mitigation of the environmental impacts of road infrastructure during all phases of life e.g. construction, operation and end-of-life disposal (as required). Life-cycle analysis (LCA), a method of quantification of all stages of life, has recently been studied to explore all the environmental components of road projects due to limitations of generic environmental assessments. The LCA ensures collection and assessment of the inputs and outputs relating to any potential environmental factor of any system throughout its life. However, absence of a defined system boundary covering all potential environmental components restricts the findings of the current LCA studies. A review of the relevant published LCA studies has identified that environmental components such as rolling resistance of pavement, effect of solar radiation on pavement(albedo), traffic congestion during construction, and roadway lighting & signals are not considered by most of the studies. These components have potentially higher weightings for environment damage than several commonly considered components such as materials, transportation and equipment. This paper presents the findings of literature review, and suggests a system boundary model for LCA study of road infrastructure projects covering potential environmental components.

Experimental and numerical characteristics of portable water-filled road safety barrier system under different impact conditions

This research has developed an innovative road safety barrier system that will enhance roadside safety. In doing so, the research developed new knowledge in the field of road crash mitigation for high speed vehicle impact involving plastic road safety barriers. This road safety barrier system has the required feature to redirecting an errant vehicle with limited lateral displacement. Research was carried out using dynamic computer simulation technique support by experimental testing. Future road safety barrier designers may use the information in this research as a design guideline to improve the performance and redirectional capability of the road safety barrier system. This will lead to better safety conditions on the roadways and potentially save lives.

Revolute joint approach to model joint mechanism in water-filled road safety barriers

Portable water-filled road barriers (PWFB) are roadside structures placed on temporary construction zones to separate work site from traffic. Recent changes in governing standards require PWFB to adhere to strict compliance in terms of lateral displacement and vehicle redirectionality. Actual PWFB test can be very costly, thus researchers resort to Finite Element Analysis (FEA) in the initial designs phase. There has been many research conducted on concrete barriers and flexible steel barriers using FEA, however not many was done pertaining to PWFB. This research probes a new technique to model joints in PWFB. Two methods to model the joining mechanism are presented and discussed in relation to its practicality and accuracy. Moreover, the study of the physical gap and mass of the barrier was investigated. Outcome from this research will benefit PWFB research and allow road barrier designers better knowledge in developing the next generation of road safety structures.

Impact and energy absorption of portable water-filled road safety barrier system fitted with foam

Portable water-filled barriers (PWFBs) are roadside appurtenances that are used to prevent errant vehicles from penetrating into temporary construction zones on roadways. A numerical model of the composite PWFB, consisting of a plastic shell, steel frame, water and foam was developed and validated against results from full scale experimental tests. This model can be extended to larger scale impact cases, specifically ones that include actual vehicle models. The cost-benefit of having a validated numerical model is significant and this allows the road barrier designer to conduct extensive tests via numerical simulations prior to standard impact tests Effects of foam cladding as additional energy absorption material in the PWFB was investigated. Different types of foam were treated and it was found that XPS foam was the most suitable foam type. Results from this study will aid PWFB designers in developing new generation of roadside structures which will provide enhanced road safety.

Effect of joint mechanism on vehicle redirectional capability of water-filled road safety barrier systems

Portable water-filled barriers (PWFBs) are roadside appurtenances that prevent vehicles from penetrating into temporary construction zones on roadways. PWFBs are required to satisfy the strict regulations for vehicle re-direction in tests. However, many of the current PWFBs fail to re-direct the vehicle at high speeds due to the inability of the joints to provide appropriate stiffness. The joint mechanism hence plays a crucial role in the performance of a PWFB system at high speed impacts. This paper investigates the desired features of the joint mechanism in a PWFB system that can re-direct vehicles at high speeds, while limiting the lateral displacement to acceptable limits. A rectangular “wall” representative of a 30 m long barrier system was modeled and a novel method of joining adjacent road barriers was introduced through appropriate pin-joint connections. The impact response of the barrier “wall” and the vehicle was obtained and the results show that a rotational stiffness of 3000 kNm/rad at the joints seems to provide the desired features of the PWFB system to re-direct impacting vehicles and restrict the lateral deflection. These research findings will be useful to safety engineers and road barrier designers in developing a new generation of PWFBs for increased road safety.

Sustainability outcomes of infrastructure sustainability rating schemes for road projects

The construction and operation of infrastructure assets can have significant impact on society and the region. Using a sustainability assessment framework can be an effective means to build sustainability aspects into the design, construction and operation of infrastructure assets. The conventional evaluation processes and procedures for infrastructure projects do not necessarily measure the qualitative/quantitative effectiveness of all aspects of sustainability: environment, social wellbeing and economy. As a result, a few infrastructure sustainability rating schemes have been developed with a view to assess the level of sustainability attained in the infrastructure projects. These include: Infrastructure Sustainability (Australia); CEEQUAL (UK); and Envision (USA). In addition, road sector specific sustainability rating schemes such as Greenroads (USA) and Invest (Australia) have also been developed. These schemes address several aspects of sustainability with varying emphasis (weightings) on areas such as: use of resources; emission, pollution and waste; ecology; people and place; management and governance; and innovation. The attainment of sustainability of an infrastructure project depends largely on addressing the whole-of-life environmental issues. This study has analysed the rating schemes’ coverage of different environmental components for the road infrastructure under the five phases of a project: material, construction, use, maintenance and end-of-life. This is based on a comprehensive life cycle assessment (LCA) system boundary. The findings indicate that there is a need for the schemes to consider key (high impact) life cycle environmental components such as traffic congestion during construction, rolling resistance due to surface roughness and structural stiffness of the pavement, albedo, lighting, and end-of-life management (recycling) to deliver sustainable road projects.

Towards increased road safety : real-time decision making for driverless city vehicles

This work elaborates on the topic of decision making for driverless city vehicles, particularly focusing on the aspects on how to develop a reliable approach which meets the requirements of safe city traffic. Decision making in this context refers to the problem of identifying the most appropriate driving maneuver to be performed in a given traffic situation. The overall decision making problem is decomposed into two consecutive stages. The first stage is safety-crucial, representing the decision regarding the set of feasible driving maneuvers. The second stage represents the decision regarding the most appropriate driving maneuver from the set of feasible ones. The developed decision making approach has been implemented in C++ and initially tested in a 3D simulation environment and, thereafter, in real-world experiments. The real-world experiments also included the integration of wireless communication between vehicles.

Cyclone Tracy and the road to improving wind-resistant design

Early on Christmas morning 1974, tropical cyclone Tracy devastated the city of Darwin leaving only 6 per cent of the city’s housing habitable and instigating the evacuation of 75 per cent of its population. The systematic failure of so much of Darwin’s building stock led to a humanitarian disaster that proved the impetus for an upheaval of building regulatory and construction practices throughout Australia. Indeed, some of the most enduring legacies of Tracy have been the engineering and regulatory steps taken to ensure the extent of damage would not be repeated. This chapter explores these steps and highlights lessons that have led to a national building framework and practice at the fore of wind-resistant design internationally.

Organizational work-related road safety situational analysis: More than just an audit tool

Although safety statistics indicate that road crashes are the most common form of work-related fatalities, many organizations fail to treat company vehicles in the same manner as other physical safety hazards within the workplace. Traditionally, work-related road safety has targeted primarily driver-related issues and not adequately addressed organizational processes, such as the organizations’ safety system and risk management processes and practice. This inadequacy generally stems from a lack of specific contextual knowledge and basic requirements to improve work-related road safety, including the supporting systems to ensure any intervention strategy or initiative’s ongoing effectiveness. Therefore, informed by previous research and based on a case study methodology, the Organizational Work-Related Road Safety Situational Analysis was developed to assess organizations’ current work-related road safety system, including policy, procedures, processes and practice. The situational analysis tool is similar to a safety audit however is more comprehensive in detail, application and provides sufficient evidence to enable organizations to mitigate and manage their work-related road safety risks. In addition, data collected from this process assists organizations in making informed decisions regarding intervention strategy design, development, implementation and ongoing effectiveness. This paper reports on the effectiveness of the situational analysis tool to assess WRRS systems across five differing and diverse organizations; including gas exploration and mining, state government, local government, and not for profit/philanthropy. The outcomes of this project identified considerable differences in the degree by which the organizations’ addressed work-related road safety across their vehicle fleet operations and provides guidelines for improving organizations’ work-related road safety systems.

Security and Privacy in Vehicular Ad-Hoc Networks : Survey and the Road Ahead

Vehicular Ad-hoc Networks (VANETs) can make roads safer, cleaner, and smarter. It can offer a wide range of services, which can be safety and non-safety related. Many safety-related VANETs applications are real-time and mission critical, which would require strict guarantee of security and reliability. Even non-safety related multimedia applications, which will play an important role in the future, will require security support. Lack of such security and privacy in VANETs is one of the key hindrances to the wide spread implementations of it. An insecure and unreliable VANET can be more dangerous than the system without VANET support. So it is essential to make sure that “life-critical safety” information is secure enough to rely on. Securing the VANETs along with appropriate protection of the privacy drivers or vehicle owners is a very challenging task. In this work we summarize the attacks, corresponding security requirements and challenges in VANETs. We also present the most popular generic security policies which are based on prevention as well detection methods. Many VANETs applications require system-wide security support rather than individual layer from the VANETs’ protocol stack. In this work we will review the existing works in the perspective of holistic approach of security. Finally, we will provide some possible future directions to achieve system-wide security as well as privacy-friendly security in VANETs.

Road infrastructure vulnerability to groundwater table variation due to sea level rise

This study was conducted to assess the vulnerability of coastal road infrastructures due to climate change induced sea level rise and extreme weather conditions through the estimation of road subgrade strength reduction as a result of changes in soil moisture content. The study area located in the Gold Coast, Australia highlighted that the risk is significant. In wet seasons or areas with wet condition, the groundwater table is already high, so even a small change in the groundwater table can raise the risk of inundation; particularly, in areas with existing shallow groundwater. The predicted risk of a high groundwater table on road infrastructure is a long-term hazard. Therefore, there is time to undertake some management plans to decrease the possible risks, for instance, some deep root plants could be planted along the roads with a high level of risk, to decrease the groundwater table elevation.

Beyond the barriers : road construction safety issues from the office and the roadside

Conceptually, the management of safety at roadworks can be seen in a three level framework. At the regulatory level, roadworks operate at the interface between the work environment, governed by workplace health and safety regulations, and the road environment, which is subject to road traffic regulations and practices. At the organizational level, national, state and local governments plan and purchase road construction and maintenance which are then delivered in-house or tendered out to large construction companies who often subcontract multiple smaller companies to supply services and labor. At the operational level, roadworks are difficult to isolate from the general public, hindering effective occupational health and safety controls. This study, from the State of Queensland, Australia, examines how well this tripartite framework functions. It includes reviews of organizational policy and procedures documents; interviews with 24 subject matter experts from various road construction and maintenance organizations, and on-site interviews with 66 road construction personnel. The study identified several factors influencing the translation of safety policies into practice including the cost of safety measures in the context of competitive tendering, lack of firm evidence of the effectiveness of safety measures, and pressures to minimize disruption to the travelling public.

On-road rapid identification of high-polluting transport buses

Exhaust emissions from motor vehicles vary widely and depend on factors such as engine operating conditions, fuel, age, mileage and service history. A method has been devised to rapidly identify high-polluting vehicles as they travel on the road. The method is able to monitor emissions from a large number of vehicles in a short time and avoids the need to conduct expensive and time consuming tests on chassis dynamometers. A sample of the exhaust plume is captured as each vehicle passes a roadside monitoring station and the pollutant emission factors are calculated from the measured concentrations using carbon dioxide as a tracer. Although, similar methods have been used to monitor soot and gaseous mass emissions, to-date it has not been used to monitor particle number emissions from a large fleet of vehicles. This is particularly important as epidemiological studies have shown that particle number concentration is an important parameter in determining adverse health effects. The method was applied to measurements of particle number emissions from individual buses in the Brisbane City Council diesel fleet operating on the South-East Busway. Results indicate that the particle number emission factors are gamma- distributed, with a high proportion of the emissions being emitted by a small percentage of the buses. Although most of the high-emitters are the oldest buses in the fleet, there are clear exceptions, with some newer buses emitting as much. We attribute this to their recent service history, particularly pertaining to improper tuning of the engines. We recommend that a targeted correction program would be a highly effective measure in mitigating urban environmental pollution.

On-road driver sleepiness : what are Australian drivers experiences and awareness of sleepiness while driving?

Objectives: Driver sleepiness contributes substantially to road crash incidents. Simulator and on-road studies clearly reveal an impairing effect from sleepiness for driving ability. However, drivers might not appreciate the dangerousness of driving while sleepy and this could translate to their on-road driving behaviours. This study sought to determine drivers’ on-road experiences of sleepiness, their sleep habits, and personal awareness of the signs of sleepiness. Methods: Participants were a random selection of 92 drivers travelling on a major highway in the state of Queensland, Australia, who were stopped by Police as part of routine drink driving operations. Participants completed a brief questionnaire that included: demographic details, awareness and on-road experiences of sleepy driving, and sleep habits. A modified version of the Karolinska Sleepiness Scale (KSS) was used to assess subjective sleepiness during the last 15 minutes of driving. Results: Participants rating of subjective sleepiness was quite low with 90% reporting at or below 3 on the KSS. Participants were reasonably aware of the signs of sleepiness; with a number of these correlated with on-road experiences. The participants sleep debt correlated with their alertness (r = -.30) and the hours spent driving (r = .38). Conclusions: These results suggest that drivers had moderate or substantial experience of driving when sleepy and many were aware of the signs of sleepiness. As many of the participants reported driving long distances after suboptimal sleep durations, it is possible that their risk perception of the dangerousness of sleepy driving maybe erroneous.

Revisiting the adoption of innovative products on Australian road infrastructure projects

Construction product innovation can exert a positive influence on project and industry performance. However, guidance is scarce on product innovation diffusion for road infrastructure, in contrast to the large body of literature on the manufacturing industry. A conceptual framework is proposed to understand these processes. Advice is given to managers based on the framework and a large quantitative survey. The framework focuses on contextual characteristics that influence the decision to adopt new-to-industry product innovation, as part of a diffusion process. Case study data are interpreted within the revised framework to test its value and disaggregate the broad obstacles to innovation. A large quantitative survey was then conducted to rank the relative importance of the obstacles constraining the adoption of innovative products on road construction projects. The three most important obstacles were found to be: (1) overemphasis on up-front project costs during tender stage; (2) disagreement over who carries the risk of new product failure; and (3) adversarial contract relations. The results suggest refinements to the conceptual framework to make it a more powerful tool for categorizing and analysing construction innovation obstacles. Results also suggest well-resourced repeat interactions within complementary procurement and regulatory systems will enhance the project teams’ ability to recognize and address innovation obstacles. Further, improved relationships are expected to decrease the need for an overly conservative approach to product approval and prescriptive specifications.